Feature/packaging

[JeltevanBoheemen]

This PR aims to make a full package out of sastadev.

• Make an installable package of all the sastadev modules, rather than a limited subset.
• Configuration
  • The implementation may seem weird, but I've exhausted options to do it in a different way that ensures both sasta and sastadev run well.
• Proper test architecture
  • Many of the existing 'tests' are skipped because they do not produce a result, the result is dependent on locally available files, or they produce errors. We will aim to fix this at a later date.

For the individual reviewers:

• @JanOdijk

  • This has some implications for how you write and use the code, but I have tried to keep these to a minimum. You will need to install the package locally (see README) to work on it. Also, mind the configuration, both setting and reading it.
  • Please try to follow the installation instructions, and let me know if anything is unclear or does not work. It is probably required that any sastadev references in your PATH are removed, so only the installed package is read.

• @bbonf , @Meesch

  • Can you test this in auchann? Clone, install locally (e.g. `pip install /Users/my_name/projects/sastadev' and run the tests.
  • General code review. Most of the changes are moved files.

[bbonf]

This requires minor changes in mwe-query, which should be merged when the PR is done: https://github.com/UUDigitalHumanitieslab/mwe-query/pull/9