Merge pull request #87 from csmith/master

Add JUEL.

build.gradle

         compile group: 'org.slf4j', name: 'slf4j-api', version:'1.7.10'
         compile group: 'com.squareup.dagger', name: 'dagger', version: '1.2.1'
         compile group: 'com.google.guava', name:'guava', version: '18.0'
+
         compile group: 'net.engio', name: 'mbassador', version: '1.2.0'
+        compile group: 'de.odysseus.juel', name: 'juel-api', version: '2.2.7'
+        compile group: 'de.odysseus.juel', name: 'juel-impl', version: '2.2.7'
+        compile group: 'de.odysseus.juel', name: 'juel-spi', version: '2.2.7'
 
         testCompile group: 'junit', name: 'junit', version: '4.12'
         testCompile group: 'org.mockito', name: 'mockito-core', version: '1.10.17'