Implement logging and metrics

[rorymcgrath]

Add different levels of logging to code to help with debugging and identifying bottlenecks.

[lukostaz]

@rorymcgrath can you take a look whether this has not introduced a regression in 9a547b7a28f877c4b2ea5b5cb0a60a3e4386db71?

Sphinx logs of the first reported failure (March 8th)

[rtd-command-info] start-time: 2019-03-08T15:18:41.597007Z, end-time: 2019-03-08T15:18:42.128740Z, duration: 0, exit-code: 2
python /home/docs/checkouts/readthedocs.org/user_builds/accenture-labs-ampligraph/envs/latest/bin/sphinx-build -T -E -b readthedocs -d _build/doctrees-readthedocs -D language=en . _build/html
Running Sphinx v1.7.9

Traceback (most recent call last):
  File "/home/docs/checkouts/readthedocs.org/user_builds/accenture-labs-ampligraph/envs/latest/lib/python3.7/site-packages/sphinx/config.py", line 161, in __init__
    execfile_(filename, config)
  File "/home/docs/checkouts/readthedocs.org/user_builds/accenture-labs-ampligraph/envs/latest/lib/python3.7/site-packages/sphinx/util/pycompat.py", line 150, in execfile_
    exec_(code, _globals)
  File "conf.py", line 26, in <module>
    import ampligraph
  File "/home/docs/checkouts/readthedocs.org/user_builds/accenture-labs-ampligraph/envs/latest/lib/python3.7/site-packages/ampligraph/__init__.py", line 8, in <module>
    logging.config.fileConfig(fname=os.path.join(os.path.abspath(os.path.dirname(__file__)),'logger.conf'), disable_existing_loggers=False)
  File "/home/docs/.pyenv/versions/3.7.1/lib/python3.7/logging/config.py", line 71, in fileConfig
    formatters = _create_formatters(cp)
  File "/home/docs/.pyenv/versions/3.7.1/lib/python3.7/logging/config.py", line 104, in _create_formatters
    flist = cp["formatters"]["keys"]
  File "/home/docs/.pyenv/versions/3.7.1/lib/python3.7/configparser.py", line 958, in __getitem__
    raise KeyError(key)
KeyError: 'formatters'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/docs/checkouts/readthedocs.org/user_builds/accenture-labs-ampligraph/envs/latest/lib/python3.7/site-packages/sphinx/cmdline.py", line 303, in main
    args.warningiserror, args.tags, args.verbosity, args.jobs)
  File "/home/docs/checkouts/readthedocs.org/user_builds/accenture-labs-ampligraph/envs/latest/lib/python3.7/site-packages/sphinx/application.py", line 163, in __init__
    confoverrides or {}, self.tags)
  File "/home/docs/checkouts/readthedocs.org/user_builds/accenture-labs-ampligraph/envs/latest/lib/python3.7/site-packages/sphinx/config.py", line 167, in __init__
    raise ConfigError(CONFIG_ERROR % traceback.format_exc())
sphinx.errors.ConfigError: There is a programable error in your configuration file:

Traceback (most recent call last):
  File "/home/docs/checkouts/readthedocs.org/user_builds/accenture-labs-ampligraph/envs/latest/lib/python3.7/site-packages/sphinx/config.py", line 161, in __init__
    execfile_(filename, config)
  File "/home/docs/checkouts/readthedocs.org/user_builds/accenture-labs-ampligraph/envs/latest/lib/python3.7/site-packages/sphinx/util/pycompat.py", line 150, in execfile_
    exec_(code, _globals)
  File "conf.py", line 26, in <module>
    import ampligraph
  File "/home/docs/checkouts/readthedocs.org/user_builds/accenture-labs-ampligraph/envs/latest/lib/python3.7/site-packages/ampligraph/__init__.py", line 8, in <module>
    logging.config.fileConfig(fname=os.path.join(os.path.abspath(os.path.dirname(__file__)),'logger.conf'), disable_existing_loggers=False)
  File "/home/docs/.pyenv/versions/3.7.1/lib/python3.7/logging/config.py", line 71, in fileConfig
    formatters = _create_formatters(cp)
  File "/home/docs/.pyenv/versions/3.7.1/lib/python3.7/logging/config.py", line 104, in _create_formatters
    flist = cp["formatters"]["keys"]
  File "/home/docs/.pyenv/versions/3.7.1/lib/python3.7/configparser.py", line 958, in __getitem__
    raise KeyError(key)
KeyError: 'formatters'


Configuration error:
There is a programable error in your configuration file:

Traceback (most recent call last):
  File "/home/docs/checkouts/readthedocs.org/user_builds/accenture-labs-ampligraph/envs/latest/lib/python3.7/site-packages/sphinx/config.py", line 161, in __init__
    execfile_(filename, config)
  File "/home/docs/checkouts/readthedocs.org/user_builds/accenture-labs-ampligraph/envs/latest/lib/python3.7/site-packages/sphinx/util/pycompat.py", line 150, in execfile_
    exec_(code, _globals)
  File "conf.py", line 26, in <module>
    import ampligraph
  File "/home/docs/checkouts/readthedocs.org/user_builds/accenture-labs-ampligraph/envs/latest/lib/python3.7/site-packages/ampligraph/__init__.py", line 8, in <module>
    logging.config.fileConfig(fname=os.path.join(os.path.abspath(os.path.dirname(__file__)),'logger.conf'), disable_existing_loggers=False)
  File "/home/docs/.pyenv/versions/3.7.1/lib/python3.7/logging/config.py", line 71, in fileConfig
    formatters = _create_formatters(cp)
  File "/home/docs/.pyenv/versions/3.7.1/lib/python3.7/logging/config.py", line 104, in _create_formatters
    flist = cp["formatters"]["keys"]
  File "/home/docs/.pyenv/versions/3.7.1/lib/python3.7/configparser.py", line 958, in __getitem__
    raise KeyError(key)
KeyError: 'formatters'

[rorymcgrath]

Bug report above have been moved to separate issue. #38

[rorymcgrath]

Issue has been subdivide into it's smaller components. Issues is now covered by #39 #40 #41