Added tests to tp_install

[alvagante]

Before submitting your PR

1. Open an issue and refer to its number in your PR title
2. If it's a bug and you have the solution, go on with the PR!
3. If it's an enhancement, please wait for our feedback before starting to work on it
4. Please run puppet-lint on your code and ensure it's compliant

After submitting your PR

1. Verify Travis checks and eventually fix the errors
2. Feel free to ping us if we don't reply promptly

[alvagante]

	2 Warnings
⚠️	Unless you’re refactoring existing code, please update CHANGELOG.md.
⚠️	Big PR! Big changes, big things may happen! Check them.

	2 Messages
📖	Changes in tests but not in manifests. If they affect tests result, in theory this should not happen.
📖	There are changes on Hiera data files. They will probably affect one or more params.

Here's an example of a CHANGELOG.md entry:

* [#41](https://github.com/example42/puppet-tp/pull/41): Added tests to tp_install - [@alvagante](https://github.com/alvagante).

Generated by 🚫 Danger

[coveralls]

Coverage increased (+0.1%) to 93.783% when pulling bef74e1 on more_tests into 10b4da5 on master.

[coveralls]

Coverage increased (+0.5%) to 94.19% when pulling 7e57efb on more_tests into 10b4da5 on master.