Added coverage testing
Fix coverage testing
Merge pull request #14 from astrofrog/coverage

Add coverage testing
Add entries to .gitignore
Remove _overlap_wrapper.c
Remove overlap.py, will be replaced by Cython file
Add overlapArea.h
Add _overlap.pyx
Change overlap wrapper to Cython
Remove a test function that I committed accidentally.
Fix test_overlap
Install Cython on travis-ci