Create tests

[randyheydon]

Automated tests are very helpful in maintaining a code base. All of BCAM's geometry calculations are well-suited for testing; I/O and GUI code is a little more difficult to test, but still very possible.

@snegovick, I'll start working on this, but I want your input before I get started. I'd like to write the tests using pytest, but that would add another external dependency. If you'd prefer to keep everything simpler, I could instead use the standard library's unittest package. Let me know what you think.

[snegovick]

Hm I dont mind adding pytest if this dependency is only needed during dev time and can be omitted during package build time. I mean its ok for developers, but it shouldnt be required for end users. If this can be done, then im ok with pytest.

[randyheydon]

Yes, this would only be needed to run tests, not to run the program. I'll go ahead with pytest then. Thanks.

[randyheydon]

I've put the framework in place for generating a development environment and automatically running tests. Details on use are in CONTRIBUTING.md. Now we just need to write those tests :)

[snegovick]

Thank you, thats quite impressive !

[snegovick]

Will later add test-writting tasks per module