Merge pull request #12176 from edx/robrap/linter-javascript

TNL-4325: Linter Enhancements for JavaScript files

scripts/tests/templates/test.coffee

+var x = "<string>" + message + "</strong>"
+var template = "<%= invalid %>"

scripts/tests/templates/test.js

+var message = "Rock & Roll";
+var x = "<string>" + message + "</strong>";
+var template = "<%= invalid %>";
+// quiet the linter
+alert(x);
+alert(template);

scripts/tests/templates/test.underscore

+<%= invalid %>