Small fix for selectors.

library/src/main/res/drawable/md_selector.xml

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<selector xmlns:android="http://schemas.android.com/apk/res/android" android:enterFadeDuration="@android:integer/config_shortAnimTime" android:exitFadeDuration="@android:integer/config_shortAnimTime">
+<selector xmlns:android="http://schemas.android.com/apk/res/android" android:exitFadeDuration="@android:integer/config_shortAnimTime">
 
     <item android:state_pressed="true" android:drawable="@drawable/md_item_selected" />
     <item android:drawable="@drawable/md_transparent" />

library/src/main/res/drawable/md_selector_dark.xml

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<selector xmlns:android="http://schemas.android.com/apk/res/android" android:enterFadeDuration="@android:integer/config_shortAnimTime" android:exitFadeDuration="@android:integer/config_shortAnimTime">
+<selector xmlns:android="http://schemas.android.com/apk/res/android" android:exitFadeDuration="@android:integer/config_shortAnimTime">
 
     <item android:state_pressed="true" android:drawable="@drawable/md_item_selected_dark" />
     <item android:drawable="@drawable/md_transparent" />