Write Unit tests to cover basic functionality

[nugmanoff]

Aim is to cover basic functionality with unit tests using bats

Basic outline of what we have to cover:

• insertion into target
• insertion into group ( 1. # comment group, 2. def group )
• insertion into root
• reserved word skipping tests (repeat insertion test but with condition to skip reserved words)
• dependency options insertion, check that all pod options are inserted correctly, for example:

pod 'Alamofire', path => '/some/local/path' # ensure that path option is correct

(You can follow Podfile syntax reference to ensure correctness of options being tested)