Update build version code to 18

Author: ataffanel

AndroidManifest.xml

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
     package="se.bitcraze.crazyfliecontrol2"
-    android:versionCode="17"
+    android:versionCode="18"
     android:versionName="0.7.2" >
 
     <uses-feature