Release 0.5.2

[calum-chamberlain]

Its time for a new version of EQcorrscan, first are there any open issues or pull-requests that need to be finished?*

To-do before release

• Check docs;
• Make sure changes are represented in CHANGES.md;
• Bump version number;
• Merge develop into master;
• Release a release candidate on github;
• Test release candidate on conda-forge: see pr 4;

If release candidate works on conda-forge then:

• Generate full release on github;
• Get DOI of new version from zenodo and update master README.md
• Release on PyPi (python setup.py sdist; python -m twine upload dist/*);
• Generate PR for eqcorrscan-feedstock from PyPi release;
• Email google-groups email list.