Java 7 Source compatibility results in gradle build errors.

[nflearl]

Running a gradle build with sourceCompatibility set to '1.7 results in the following error:

$ gradle build
:compileJava
Download http://localhost:8080/netkernel-maven/urn/com/ten60/core/layer0/1.109.5 7/layer0-1.109.57.pom
Download http://localhost:8080/netkernel-maven/urn/com/ten60/core/netkernel.api/ 4.2.5/netkernel.api-4.2.5.pom
Download http://localhost:8080/netkernel-maven/urn/com/ten60/core/netkernel.impl /4.37.24/netkernel.impl-4.37.24.pom
Download http://localhost:8080/netkernel-maven/urn/com/ten60/core/layer0/1.109.5 7/layer0-1.109.57.jar
Download http://localhost:8080/netkernel-maven/urn/com/ten60/core/netkernel.api/ 4.2.5/netkernel.api-4.2.5.jar
Download http://localhost:8080/netkernel-maven/urn/com/ten60/core/netkernel.impl /4.37.24/netkernel.impl-4.37.24.jar
:compileJava FAILED

FAILURE: Build failed with an exception.

• What went wrong:
  Execution failed for task ':compileJava'.

  invalid source release: 1.7

Setting sourceCompatibility to 1.6 works fine.