Merge pull request #209 from GoogleCloudPlatform/java6compat

Set java language level to 6 for build

Author: patflynn

build.gradle

@@ -29,6 +29,8 @@ subprojects {
     }
 
     compileJava.dependsOn ':loadIdea'
+    sourceCompatibility = 1.6
+    targetCompatibility = 1.6
 
 }
 

common-lib/build.gradle

@@ -1,7 +1,5 @@
 apply plugin: 'java'
 
-sourceCompatibility = 1.5
-
 repositories {
     mavenCentral()
 }