Implement Tests

[casey-SK]

Implement tests for the following:

1. Tests of all successful outcomes of the init subcommand
   • with just name argument
   • with name and sdk path
   • with name, sdk path, and nimbase path
   • ensure --overwrite works as intended.
2. Tests of all successful outcomes of the `build subcommand
3. Tests which of all likely events where error messages have been defined

[casey-SK]

I plan on starting this on the weekend

[casey-SK]

after some pondering, I now realize that testing all possible outcomes of the command line args is a little overboard. And I also didn't mention creating any tests for the actual wrappers themselves, which I think I will also try to do.