rename __tests__ to tests to fix #20

tests/helpers/changeExtensionIcon.spec.js

@@ -0,0 +1,10 @@
+var chai = require('chai');
+var expect = chai.expect;
+
+import changeExtensionIcon from '../../assets/js/helpers/changeExtensionIcon';
+
+describe('changeExtensionIcon', function() {
+	it('should be a function', function() {
+		expect(changeExtensionIcon).to.be.a('function');
+	});
+});