Bump coveralls from 0.4.2 to 1.6.0

Bumps [coveralls](https://github.com/coveralls-clients/coveralls-python) from 0.4.2 to 1.6.0.
- [Release notes](https://github.com/coveralls-clients/coveralls-python/releases)
- [Changelog](https://github.com/coveralls-clients/coveralls-python/blob/master/CHANGELOG.md)
- [Commits](TheKevJames/coveralls-python@0.4.2...1.6.0)

Signed-off-by: dependabot[bot] <support@dependabot.com>

requirements-test.txt

@@ -1,7 +1,7 @@
 -r requirements.txt
 
 coverage==3.7.1
-coveralls==0.4.2
+coveralls==1.6.0
 flake8==3.6.0
 mock==1.0.1
 tox==1.7.2