Fixes escalante/sbt-escalante#12
war artefacts missing 'WEB-INF/lib' dependencies
Add test verifying WEB-INF/lib contents and expand library filter #12
Update release script to modify versions in README after release
Update versions in root README file and adjust script to automate it
Plugin downloads a different Escalante version, if needed #13

* This can be a workaround if there's an issue with Escalante and a
newer snapshot version fixes it.
* A test has been added that verifies that Escalante runs with a
different version than the current one.
* Escalante has been updated to latest 0.3.0-SNAPSHOT.
Extend SBT plugin to support Play applications #14

* Added test for basic Play Hello World application.
* Add support for extra Play modules to be generated in descriptor
'Release Script: update README file in master to last released version=0.2.0 and escalanteVersion=0.3.0'