test: let Jasmine handle promises (#57)

* test: let Jasmine handle promises

Last in line for apache/cordova#169

* lock in portrait mode to avoid trouble on CI

cordova-paramedic runs the SauceLabs CI tests in portrait mode. For
the Android 7.0 target, it seemed as our locking to landscape interferes
with the Appium driver trying to set the app to portrait orientation.
The result is a failure to connect to the device and finally a timeout.
To avoid that, we are locking the app into portrait mode instead.

* test: verify orientation after locking

tests/tests.js

@@ -117,25 +117,11 @@ exports.defineAutoTests = function() {
     // test onchange works
     describe('window.screen.orientation', function() {
 
-        it('should successfully lock and unlock screen orientation, lock should return a promise', function(done) {
-
-            try {
-                var promise = window.screen.orientation.lock('landscape');
-                expect(promise).toBeDefined();
-                expect(typeof promise.then).toBe('function');
-                promise.then(function() {
-                    expect(window.screen.orientation.unlock).not.toThrow();
-                    done();
-                }, function(err) {
-                    expect(err).toBeDefined();
-                    fail(err);
-                    done();
-                });
-            } catch (err) {
-                fail(err);
-                done();
-            }
-
+        it('should successfully lock and unlock screen orientation', function() {
+            return window.screen.orientation.lock('portrait').then(function() {
+                expect(window.screen.orientation.type).toMatch(/^portrait-/);
+                expect(window.screen.orientation.unlock).not.toThrow();
+            });
         });
     });
 };