[WIP] Test table api

Unfinished. Commit to get a review on changes I made to the Table constructor. For some reason types were not automatically being inferred from the call to discover(data) regardless of the kind of data. I could probably simplify this more by modifying the conditionals above the statement that I added. Relatively simply fix. 
agreed, if you have a variable that will only be read from, make it global. fixtures are better suited to things that have a lot of setup/are going to be written to/databases

@brittainhard it looks like you're only using these in a few places, so i would say make them globals.