Bump Spock and Groovy test dependencies

Author: michaelklishin

Diff for: build.gradle

@@ -62,8 +62,8 @@ dependencies {
     testCompile("org.clojure:clojure:1.10.0")
     testCompile("joda-time:joda-time:2.8.2")
     testCompile("org.slf4j:slf4j-simple:1.7.10")
-    testCompile("org.codehaus.groovy:groovy-all:2.4.1")
-    testCompile("org.spockframework:spock-core:1.0-groovy-2.4")
+    testCompile("org.codehaus.groovy:groovy-all:2.5.12")
+    testCompile("org.spockframework:spock-core:1.3-groovy-2.5")
     testRuntime("cglib:cglib-nodep:3.1")
     testRuntime("org.objenesis:objenesis:2.1")
 }