Remove unnecessary check for 'err' as aws-sdk-javascript never goes in to that branch with aws-mock; Add jshint exception for unused param in function
Add test case for no instance ID specified in 'describeInstances'
Add coverage threshold to 85% (revert to pure mocha for now since arrow not work with coverage)
Merge pull request #27 from treelogic-swe/add-code-coverage

Add JS code coverage