Warnings of duplicate label inputs while building docs

[MaGering]

There are several warnings when the docs are built:

/home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/scripts/plot_conv_pp_scalars.py:docstring of plot_conv_pp_scalars:2: WARNING: duplicate label inputs, other instance in /home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/docs/optimization/optimize.rst
/home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/scripts/plot_conv_pp_scalars.py:docstring of plot_conv_pp_scalars:12: WARNING: duplicate label outputs, other instance in /home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/docs/optimization/optimize.rst
/home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/scripts/plot_conv_pp_scalars.py:docstring of plot_conv_pp_scalars:17: WARNING: duplicate label description, other instance in /home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/docs/optimization/optimize.rst
/home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/scripts/plot_dispatch.py:docstring of plot_dispatch:2: WARNING: duplicate label inputs, other instance in /home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/docs/plotting/plot_conv_pp_scalars.rst
/home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/scripts/plot_dispatch.py:docstring of plot_dispatch:11: WARNING: duplicate label outputs, other instance in /home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/docs/plotting/plot_conv_pp_scalars.rst
/home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/scripts/plot_dispatch.py:docstring of plot_dispatch:20: WARNING: duplicate label description, other instance in /home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/docs/plotting/plot_conv_pp_scalars.rst
/home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/scripts/plot_scalar_results.py:docstring of plot_scalar_results:2: WARNING: duplicate label inputs, other instance in /home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/docs/plotting/plot_dispatch.rst
/home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/scripts/plot_scalar_results.py:docstring of plot_scalar_results:10: WARNING: duplicate label outputs, other instance in /home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/docs/plotting/plot_dispatch.rst
/home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/scripts/plot_scalar_results.py:docstring of plot_scalar_results:15: WARNING: duplicate label description, other instance in /home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/docs/plotting/plot_dispatch.rst
/home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/scripts/join_scenarios.py:docstring of join_scenarios:2: WARNING: duplicate label inputs, other instance in /home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/docs/plotting/plot_scalar_results.rst
/home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/scripts/join_scenarios.py:docstring of join_scenarios:10: WARNING: duplicate label outputs, other instance in /home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/docs/plotting/plot_scalar_results.rst
/home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/scripts/join_scenarios.py:docstring of join_scenarios:15: WARNING: duplicate label description, other instance in /home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/docs/plotting/plot_scalar_results.rst
/home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/scripts/postprocess.py:docstring of postprocess:2: WARNING: duplicate label inputs, other instance in /home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/docs/postprocessing/join_scenarios.rst
/home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/scripts/postprocess.py:docstring of postprocess:14: WARNING: duplicate label outputs, other instance in /home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/docs/postprocessing/join_scenarios.rst
/home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/scripts/postprocess.py:docstring of postprocess:19: WARNING: duplicate label description, other instance in /home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/docs/postprocessing/join_scenarios.rst
/home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/scripts/build_datapackage.py:docstring of build_datapackage:2: WARNING: duplicate label inputs, other instance in /home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/docs/postprocessing/postprocess.rst
/home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/scripts/build_datapackage.py:docstring of build_datapackage:11: WARNING: duplicate label outputs, other instance in /home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/docs/postprocessing/postprocess.rst
/home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/scripts/build_datapackage.py:docstring of build_datapackage:17: WARNING: duplicate label description, other instance in /home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/docs/postprocessing/postprocess.rst
/home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/scripts/create_input_data_overview.py:docstring of create_input_data_overview:2: WARNING: duplicate label inputs, other instance in /home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/docs/preprocessing/build_datapackage.rst
/home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/scripts/create_input_data_overview.py:docstring of create_input_data_overview:9: WARNING: duplicate label outputs, other instance in /home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/docs/preprocessing/build_datapackage.rst
/home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/scripts/create_input_data_overview.py:docstring of create_input_data_overview:14: WARNING: duplicate label description, other instance in /home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/docs/preprocessing/build_datapackage.rst
/home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/scripts/prepare_conv_pp.py:docstring of prepare_conv_pp:2: WARNING: duplicate label inputs, other instance in /home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/docs/preprocessing/create_input_data_overview.rst
/home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/scripts/prepare_conv_pp.py:docstring of prepare_conv_pp:15: WARNING: duplicate label outputs, other instance in /home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/docs/preprocessing/create_input_data_overview.rst
/home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/scripts/prepare_conv_pp.py:docstring of prepare_conv_pp:22: WARNING: duplicate label description, other instance in /home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/docs/preprocessing/create_input_data_overview.rst
/home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/scripts/prepare_electricity_demand.py:docstring of prepare_electricity_demand:2: WARNING: duplicate label inputs, other instance in /home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/docs/preprocessing/prepare_conv_pp.rst
/home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/scripts/prepare_electricity_demand.py:docstring of prepare_electricity_demand:10: WARNING: duplicate label outputs, other instance in /home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/docs/preprocessing/prepare_conv_pp.rst
/home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/scripts/prepare_electricity_demand.py:docstring of prepare_electricity_demand:16: WARNING: duplicate label description, other instance in /home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/docs/preprocessing/prepare_conv_pp.rst
/home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/scripts/prepare_feedin.py:docstring of prepare_feedin:2: WARNING: duplicate label inputs, other instance in /home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/docs/preprocessing/prepare_electricity_demand.rst
/home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/scripts/prepare_feedin.py:docstring of prepare_feedin:16: WARNING: duplicate label outputs, other instance in /home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/docs/preprocessing/prepare_electricity_demand.rst
/home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/scripts/prepare_feedin.py:docstring of prepare_feedin:21: WARNING: duplicate label description, other instance in /home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/docs/preprocessing/prepare_electricity_demand.rst
/home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/scripts/prepare_heat_demand.py:docstring of prepare_heat_demand:2: WARNING: duplicate label inputs, other instance in /home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/docs/preprocessing/prepare_feedin.rst
/home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/scripts/prepare_heat_demand.py:docstring of prepare_heat_demand:22: WARNING: duplicate label outputs, other instance in /home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/docs/preprocessing/prepare_feedin.rst
/home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/scripts/prepare_heat_demand.py:docstring of prepare_heat_demand:29: WARNING: duplicate label description, other instance in /home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/docs/preprocessing/prepare_feedin.rst
/home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/scripts/prepare_re_potential.py:docstring of prepare_re_potential:36: ERROR: Unexpected indentation.
/home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/scripts/prepare_re_potential.py:docstring of prepare_re_potential:2: WARNING: duplicate label inputs, other instance in /home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/docs/preprocessing/prepare_heat_demand.rst
/home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/scripts/prepare_re_potential.py:docstring of prepare_re_potential:22: WARNING: duplicate label outputs, other instance in /home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/docs/preprocessing/prepare_heat_demand.rst
/home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/scripts/prepare_re_potential.py:docstring of prepare_re_potential:29: WARNING: duplicate label description, other instance in /home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/docs/preprocessing/prepare_heat_demand.rst
/home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/scripts/prepare_scalars.py:docstring of prepare_scalars:2: WARNING: duplicate label inputs, other instance in /home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/docs/preprocessing/prepare_re_potential.rst
/home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/scripts/prepare_scalars.py:docstring of prepare_scalars:10: WARNING: duplicate label outputs, other instance in /home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/docs/preprocessing/prepare_re_potential.rst
/home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/scripts/prepare_scalars.py:docstring of prepare_scalars:15: WARNING: duplicate label description, other instance in /home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/docs/preprocessing/prepare_re_potential.rst
/home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/scripts/prepare_vehicle_charging_demand.py:docstring of prepare_vehicle_charging_demand:2: WARNING: duplicate label inputs, other instance in /home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/docs/preprocessing/prepare_scalars.rst
/home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/scripts/prepare_vehicle_charging_demand.py:docstring of prepare_vehicle_charging_demand:11: WARNING: duplicate label outputs, other instance in /home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/docs/preprocessing/prepare_scalars.rst
/home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/scripts/prepare_vehicle_charging_demand.py:docstring of prepare_vehicle_charging_demand:17: WARNING: duplicate label description, other instance in /home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/docs/preprocessing/prepare_scalars.rst
/home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/scripts/process_re_potential.py:docstring of process_re_potential:2: WARNING: duplicate label inputs, other instance in /home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/docs/preprocessing/prepare_vehicle_charging_demand.rst
/home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/scripts/process_re_potential.py:docstring of process_re_potential:13: WARNING: duplicate label outputs, other instance in /home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/docs/preprocessing/prepare_vehicle_charging_demand.rst
/home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/scripts/process_re_potential.py:docstring of process_re_potential:24: WARNING: duplicate label description, other instance in /home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/docs/preprocessing/prepare_vehicle_charging_demand.rst
/home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/docs/whats_new/v0-0-1.rst:2: WARNING: duplicate label v0.0.1, other instance in /home/docs/checkouts/readthedocs.org/user_builds/oemof-b3/checkouts/release-0.0.1/docs/whats_new.rst