Improved homog-test.js' mutation score to 0.8

Mutation analysis was performed on homog-test.js with Mutator (http://ortask.com/mutator/). I improved the test suite's mutation score from 0.63 to 0.8. 

In order to get to raise the quality of the test suite to 1.0, the following issue needs to be resolved: https://github.com/rockbot/vektor/issues/22