add specs for app.launcher api

fix linter errors

spec/api-app-spec.js

@@ -284,4 +284,37 @@ describe('app module', function () {
       })
     })
   })
+
+  describe('app.launcher API', function () {
+    it('should be available on linux', function () {
+      if (process.platform !== 'linux') {
+        assert.equal(app.launcher, undefined)
+      } else {
+        assert.notEqual(app.launcher, undefined)
+      }
+    })
+
+    it('should be possible to set a badge count on supported environments', function () {
+      if (process.platform === 'linux' &&
+          app.launcher.isCounterBadgeAvailable()) {
+        app.launcher.setBadgeCount(42)
+        assert.equal(app.launcher.getBadgeCount(), 42)
+      }
+    })
+
+    it('should be possible to set a badge count on unity', function () {
+      if (process.platform === 'linux' &&
+          app.launcher.isUnityRunning()) {
+        assert.equal(app.launcher.isCounterBadgeAvailable(), true)
+      }
+    })
+
+    it('should not be possible to set a badge counter on unsupported environments', function () {
+      if (process.platform === 'linux' &&
+          !app.launcher.isCounterBadgeAvailable()) {
+        app.launcher.setBadgeCount(42)
+        assert.equal(app.launcher.getBadgeCount(), 0)
+      }
+    })
+  })
 })