Create tests for functions and enable continuous integration on travis

[samueltwum1]

The only means of testing now is running the software which only reveals bugs during usage. This works fine so far but sometimes the bugs encountered can be avoided if this repo has scripts that performs unit tests and integration tests for every commit and merge to master made.

The plan will be to first write unit tests for individual functions in the different classes and then explore how we can use travis to set up integration tests for continuous integration.