Releasing remote server

Run tests on different operating systems and with different interpreters. See test/README.rst for more details.
Set $VERSION shell variable to ease copy-pasting further commands:
```
VERSION=x.y
```

Update __version__ in src/robotremoteserver.py:

# Linux (GNU sed):
sed -i "s/__version__ = .*/__version__ = '$VERSION'/" src/robotremoteserver.py
# OS X (BSD sed):
sed -i "" "s/__version__ = .*/__version__ = '$VERSION'/" src/robotremoteserver.py
# Verify changes and commit:
git diff
git commit -m "Updated __version__ to $VERSION" src/robotremoteserver.py && git push

Tag:

git tag -a $VERSION -m "Release $VERSION" && git push --tags

Create and upload distribution:
```
python setup.py sdist upload
```
Verify that PyPI page looks good.

Test that installation works:

pip install robotremoteserver --upgrade

__version__ back to devel:

# Linux (GNU sed):
sed -i "s/__version__ = .*/__version__ = 'devel'/" src/robotremoteserver.py
# OSX (BSD sed):
sed -i "" "s/__version__ = .*/__version__ = 'devel'/" src/robotremoteserver.py
# Verify changes and commit:
git diff
git commit -m "__version__ back to devel" src/robotremoteserver.py && git push

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