Instrumentation

Added few tests for instrumentation of login screen. At the moment it does only checks for error messages on text field. I will need to come up with way any developer be able to safely use his in game credentials for tests without need to commit them to repo.

Part of the commit is spoon library that generates nice test page for instrumentation tests with screenshots.
After successful `mvn clean install` in project root (in my case /Users/Peter/github/Battle-Chat) do

````
cd instrumentation
mvn spoon:run
````
You will find result in instrumentation/target/spoon-out, just open index.html in any browser. This step can be run on multiple devices simultaneously and  final result will be available in single report. 

Have fun