Validation of 'id' attribute required for path, course, and lesson JSON files

[jdmedlock]

Issue Description & Expected Outcome:
Validation of 'id' attribute is missing for path, course, and lesson JSON files in the Mocha test suite.

Symptoms:
N/a

Steps to Recreate:
N/a

Resolution:
Added validateIdMatch() function in Mocha tests to ensure that JSON block key and "id" attribute value are the same.

Note that we are considering eliminating the "id" attribute and if so this code will need to be removed.