Licence + caveat added to Android Studio Canary cask

Casks/android-studio-canary.rb

@@ -4,7 +4,15 @@ cask :v1 => 'android-studio-canary' do
 
   url "https://dl.google.com/dl/android/studio/ide-zips/#{version}/android-studio-ide-135.1626825-mac.zip"
   homepage 'http://tools.android.com/download/studio'
-  license :unknown
+  license :apache
 
   app 'Android Studio.app'
+
+  caveats <<-EOS.undent
+    If you have Java 7 or above installed, you may want to use it as Android Studio JDK, for example:
+
+    export STUDIO_JDK=/Library/Java/JavaVirtualMachines/jdk1.8.0_25.jdk
+
+    Please take a look at this post: http://tools.android.com/recent/androidstudio1rc3_releasecandidate3released
+  EOS
 end