Tag with dev if not right on release tag (#117)

photon-server/versioningHelper.gradle

@@ -15,6 +15,8 @@ gradle.allprojects {
         } catch(Exception e) {
             tagIsh = "dev-Unknown"
         }
+        boolean isDev = tagIsh.matches(".*-[0-9]*-g[0-9a-f]*")
+        if(isDev) tagIsh = "dev-" + tagIsh
         println("Picked up version: " + tagIsh)
         return tagIsh
     }