Merge pull request #32 from csmith/master

Tell gradle to use 1.8.

build.gradle

@@ -87,8 +87,8 @@ subprojects {
         }
     }
 
-    sourceCompatibility = 1.7
-    targetCompatibility = 1.7
+    sourceCompatibility = 1.8
+    targetCompatibility = 1.8
 
     repositories.mavenCentral()