Release 0.1.0

Data format:

* Introduce observables table instead of SBML assignment rules for defining
  observation model (#244) (moves observableTransformation and noiseModel
  from the measurement table to the observables table)
* Allow initial concentrations / sizes in condition table (#238)
* Fixes and clarifications in the format documentation
* Changes in prior columns of the parameter table (#222)
* Introduced separate version number of file format, this release being
  version 1

Library:

* Adaptations to new file formats
* Various bugfixes and clean-up, especially in visualization and validator
* Parameter mapping changed to include all model parameters and not only
  those differing from the ones defined inside the SBML model
* Introduced constants for all field names and string options, replacing
  most string literals in the code (#228)
* Added unit tests and additional format validation steps
* Optional parallelization of parameter mapping (#205)
* Extended documentation (in-source and example Jupyter notebooks)