Add readme with build instructions
Remove comments generated by `gradle init`
Format sources

By hand, for now.
Use jcenter() instead of default mavenCentral()

TODO: add issue in Gradle JIRA
Use assertThat instead of assertTrue

TODO: add Gradle issue for this
Set Gradle source compatibility to Java 1.8

Note that this implicitly sets target compatibility to 1.8 as well.
Ignore IDEA artifacts

 - Import project into IDEA 13.1.1
 - Ignore generated .idea dir and .iml file

Note that IDEA respected the sourceCompatibility value of 1.8 in
build.gradle, but successful compilation required manually setting the
project SDK from 1.7 to 1.8.
Add instructions to readme on importing into IDEA
Apply IDEA tip to use Gradle source distribution

This enables richer code completion in *.gradle files
Add Travis CI configuration file

 - Per instructions at http://docs.travis-ci.com/user/languages/java
 - Add build status badge to readme
Add required field, constructor and getter to Library
Use lombok to eliminate boilerplate

 - Update README to reflect IDEA requirements