[js-testing] type checking for dates.js (#2893)

* tests for dates.js

* linting

* test fduration output

* ignore warnings in code climate

* use eslint-2 otherwise defaults to eslint-3

* test eslint 1

* remove channel rule

* disable checks

* checks for eslint engine

superset/assets/javascripts/modules/dates.js

@@ -105,4 +105,3 @@ export const epochTimeXYearsAgo = function (y) {
     .utc()
     .valueOf();
 };
-