Updates schema, fixes view/css issues, adds transaction creation endpoint and more

Adds a migration to change the transactions table so that rfid_id is a string instead of a integer. 

Fixes a view/css issue. Previously, when the charts were appended to the chart-container div on the page, the page-wrapper did not expand as well to accommodate the larger chart-container leaving gray-space in the background instead of the usual white background. I include code that recalculates the page-wrapper div height after a 500 ms timeout so that it can encompass the entire page.  

Adds a TransactionsController#create and a post route '/transactions/new' that points to it. TransactionsController#create accepts an array of JSON object data with transaction information and automatically associates the newly created transaction with the location_id of any existing hub. Includes rspec controller tests to ensure that it is working as intended.

This pull request also cleans up the various javascript and css libraries no longer being used, including the one for morris, raphael and various jquery.flot libraries.

@melissa-mccoy @ambirdsall 
Yeah, I wanted to make sure it was working correctly, since I'm still a little shaky as to how Rails reads an incoming JSON request, so I wrote tests after the fact to make sure my syntax was write. Good thing I did, because I had completely wrong the first time around!