First unit test for studentData

Added local PHPUnit framework, test class for studentData and
first test.
Unit tests for studentData
Rough skeleton of student query
Configure your own file storage path.
Successfully queries database.

One unit test (out of 2) passes.
All student data tests pass
Added error logging to studentData
Merge branch 'fb5034-QueryStudentData' of https://github.com/shawn-bellevuecollege/gravityforms-external-data-fields into shawn-bellevuecollege-fb5034-QueryStudentData