Change coverage threshold for branches

Statements, functions and lines threshold at 80% global
Branches at 75% global

gulpfile.babel.js

@@ -79,7 +79,12 @@ gulp.task('test', ['pre-test'], () => {
     .pipe(istanbul.writeReports())
     .pipe(istanbul.enforceThresholds({
         thresholds: {
-            global: 80
+            global: {
+                statements: 80,
+                branches: 75,
+                lines: 80,
+                functions: 80
+            }
         }
     }))
     .on('error', () => {