Refactor commits into temp variable

Eases readability a bit
Pluralize commit(s) only when more than one

- check test which has one commit
Move payloads outside spec for readability

Create a simple class to generate payloads and use that class to set up
our scenarios. This helps the readability of the specs.
Fix indentation
Add test for single commit

Make sure that the wording appears as we expect for a single commit.
Use Module for Payload to remove need for lets

By using a module, we can simply include it and this removes the need to
have RSpec create temporary variables. We can include it and all users
of Payloads continue to work as expected.
Merge pull request #5 from amaltson/single_commit_not_pluralized

Single commit not pluralized