Releasing clld/glottolog

Check out master and pull the latest changes:

git checkout master
git pull origin master

Check the tree and references running

glottolog check

making sure there are no ÈRRORs

Merging the BibTeX files

Update automatically created files:
- iso6393.bib: Run glottolog isobib
- benjamins.bib:
  - Switch to the clone of clld/benjamins
  - Pull the latest changes via FTP
  - Recreate benjamins.bib, running python to_bib.py
  - Switch back to clld/glottolog
  - Run glottolog copy_benjamins PATH/TO/clld/benjamins/benjamins.bib
Run glottolog bib to create build/monster-utf8.bib
Commit and push all changes to master.

Releasing

Draft a new release
Add DOI badge from ZENODO as soon as it becomes available.

Releasing `pyglottolog`

Make sure the tests pass:
```
tox -r
```
Make sure flake8 passes:
```
flake8 pyglottolog
```
Change version to the new version number in
- setup.py
- pyglottolog/__init__.py

Bump version number:

git commit -a -m "release pyglottolog <version>"

Create a release tag:

git tag -a pyglottolog-<version> -m "first version to be released on pypi"

Release to PyPI:

git checkout tags/v$1
rm dist/*
python setup.py sdist bdist_wheel
twine upload dist/*

Push to github:
```
git push origin
git push --tags
```