Gradle version bump

Change-Id: I3083c2e0ffc75019f752966e5a95dab138c82c3d
Reviewed-on: http://gerrit.dmdirc.com/3898
Reviewed-by: Greg Holmes <greg@dmdirc.com>
Automatic-Compile: DMDirc Build Manager

build.gradle

 }
 
 task wrapper(type: Wrapper) {
-    gradleVersion = '2.0'
+    gradleVersion = '2.1'
 }

gradle/wrapper/gradle-wrapper.properties

-#Sat Sep 13 23:43:53 BST 2014
+#Sun Sep 14 12:38:26 BST 2014
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-2.0-bin.zip
+distributionUrl=http\://services.gradle.org/distributions/gradle-2.1-bin.zip