updated the csvParser to be able to handle volume checking
Added the volume checking model and the ability to decide models in the pipeline config. The pipeline config now needs to have a "model" parameter for the scan pages, and the options are "VolumeCheckModel" and "RackScanModel".

The volume check page loads the csv file and verifies that the number of tubes match the input amount, and then has the capability to save to tube rack when the user clicks to save the volume quantities.

This is still a bit rough, so further improvements can be made.
Added necessary additional model parameter to pipeline config. See previous commit comment for full details.
Corrections following comments, eval removed.
Changes following comments
Merge pull request #163 from mikemases/Volume_Checking

Volume checking