Fix versions

gradle.properties

@@ -1,14 +1,19 @@
-servletApi3Version=3.1.0
-httpclientVersion=4.3.3
-springSecurityVersion=3.2.7.RELEASE
-tomcatEmbedVersion=7.0.56
-servletApi2Version=2.5
-junitVersion=4.11
-springVersion=4.1.6.RELEASE
-apacheDirServerVersion=2.0.0-M15
-springBootVersion=1.2.1.RELEASE
-log4jVersion=1.2.17
-apacheDirApiVersion=1.0.0-M20
-hamcrestVersion=1.3
+## Common libraries
+log4jVersion = 1.2.17
+springVersion = 4.1.6.RELEASE
+springBootVersion = 1.2.1.RELEASE
+springSecurityVersion = 3.2.7.RELEASE
+httpclientVersion = 4.3.3
+apacheDirServerVersion = 2.0.0-M15
+apacheDirApiVersion = 1.0.0-M20
+
+servletApi2Version = 2.5
+servletApi3Version = 3.1.0
+
+## Common testing libraries
+junitVersion = 4.11
+tomcatEmbedVersion = 7.0.56
+mockitoVersion = 1.9.5
+hamcrestVersion = 1.3
+
 version=1.0.1.BUILD-SNAPSHOT
-mockitoVersion=1.9.5