add support-v4 dependency

library/build.gradle

@@ -18,6 +18,7 @@ android {
 
 dependencies {
     compile fileTree(dir: 'libs', include: ['*.jar'])
+    compile 'com.android.support:support-v4:22.0.0@aar'
     compile 'com.android.support:appcompat-v7:22.0.0@aar'
     compile 'com.android.support:support-annotations:22.0.0'
     compile 'com.android.support:recyclerview-v7:22.0.0@aar'