Pyxenon

Raises version number

- Fixes a bug in Xenon-GRPC mixing up streams in interactive jobs.

This release fixes some bugs, adds more documentation, and has a few additions in the API.

- Includes documentation on the adaptors.
- Xenon exceptions are raised in stead of Rpc errors.
- Enums for error_type in JobStatus, QueueStatus and CopyStatus are acting as python Enums.
- Jobs can be constructed by the user.

2.2.0-py1
Fixes documentation issues.

Complete rewrite of PyXenon

What happened
PyXenon is now a client to the Xenon-GRPC package. We took this step because the different Java-Python bridges (pyjnius, jpype) were giving problems in multi-threaded environments. We now use Google's GRPC to communicate between Python and the Java implementation of Xenon. The Xenon-GRPC JAR file (including Xenon) is included in this distribution.

Documentation
The new API is documented at [ReadTheDocs](http://pyxenon.readthedocs.io), it also contains many examples.

Versioning
At the same time Xenon underwent a redesign, culminating in the release of Xenon 2.0, now 2.2. Since Xenon-GRPC (including Xenon) is included in this distribution, we keep PyXenon version numbers in sync with Xenon. If changes happen to PyXenon without a new release of Xenon, a suffix is added.

The python wrapper of Xenon, using the JPype library

Changes:
- Wrap all java classes and package in a `JavaClass` and `JavaPackage` wrapper, to avoid segmentation faults and allow importing classes from `xenon` directly.
- added `__version__` attribute.
- Removed references to jpypes internal data structures.
- README to reStructuredText
- Switched to `pytest` testing with `tox` and added a `.coveragerc` file.