Expand Table API

[awalter17]

Hello!

This PR contains changes for the table API. These changes include:

• Adding table and column types for storing primitives
• Adding tests for the new table types
• Fixing bugs with the existing table methods (including #61)
• Allowing the GenericTable class to accept multiple column types
• etc.

I have checked this branch and all commits are compiling with passing tests. Please let me know if you notice any issues or have any questions/concerns regarding this PR.

[ctrueden]

Thank you so much! Extremely nice work! :beers: