Add toml-rb gem

We want to store the glossary as a TOML file for easy
modification.

Toml: https://github.com/eMancu/toml-rb
Add glossary TOML file

All the app's terms will be stored and defined in this file.
We can later use this file to generate/updat documentation
for the app's terms
Merge pull request #5 from jacobpatton/glossary

Glossary