Change return codes

0 for success with commit, -1 for success without commit

Change-Id: I78fbf2424089f638a04076b4fd3d65fdd4ba1d16
diff --git a/crowdin_sync.py b/crowdin_sync.py
index 52f0371..9e7fea5 100755
--- a/crowdin_sync.py
+++ b/crowdin_sync.py
@@ -34,6 +34,7 @@
 # ################################# GLOBALS ################################## #
 
 _DIR = os.path.dirname(os.path.realpath(__file__))
+_COMMITS_CREATED = False
 
 # ################################ FUNCTIONS ################################# #
 
@@ -98,6 +99,8 @@
     except:
         print('Failed to push commit for %s' % name, file=sys.stderr)
 
+    _COMMITS_CREATED = True
+
 
 def check_run(cmd):
     p = subprocess.Popen(cmd, stdout=sys.stdout, stderr=sys.stderr)
@@ -367,7 +370,13 @@
     if args.download:
         download_crowdin(base_path, default_branch, (xml_android, xml_extra),
                          args.username, args.config, args.ticket)
-    print('\nDone!')
+
+    if _COMMITS_CREATED:
+        print('\nDone!')
+        sys.exit(0)
+    else
+        print('\nNothing to commit')
+        sys.exit(-1)
 
 if __name__ == '__main__':
     main()