CB-12524: Set Gradle to always build in the project directory since our tests don't run scripts from the project directory by default

.travis.yml

@@ -9,7 +9,6 @@ install:
     - npm install
     - npm install -g codecov
     - echo y | android update sdk -u --filter android-22,android-23,android-24,android-25
-    - gradle wrapper
 android:
     components:
       - tools

bin/templates/cordova/lib/builders/GradleBuilder.js

@@ -74,7 +74,7 @@ GradleBuilder.prototype.runGradleWrapper = function(gradle_cmd) {
     if(fs.existsSync(gradlePath)) {
       //Literally do nothing, for some reason this works, while !fs.existsSync didn't on Windows
     } else {
-      return spawn(gradle_cmd, ['wrapper'], {stdio: 'inherit'});
+      return spawn(gradle_cmd, ['-p', this.root, 'wrapper'], {stdio: 'inherit'});
     }
 };