Missing codecov - dependency fails installation #14

It appears the codecov package was removed from the Pypi today, which causes installation of this package to fail.

Since codecov is not actually used in the source code, it should be removed from install_requires in setup.py along with any other purely test-related requirements. If you want to do a straight pull from requirements into the setup.py configuration, you should create a requirements-dev.txt file which can be used to install development and testing requirements. Only requirements explicitly necessary for installation and use of the package should be included in install_requires