Updating buck to build OSGi JARs

Includes:
  OSGiWrapper to wrap Buck JARs
    - cfgdef file support
    - WAR file generation support
  Adding checkstyle support

Change-Id: Ia25c41f945980e4b94ad5a8bd161328fa5f79c27
diff --git a/.buckconfig b/.buckconfig
index 3270c10..2dc3441 100644
--- a/.buckconfig
+++ b/.buckconfig
@@ -5,3 +5,6 @@
   source_level = 8
   target_level = 8
 
+[download]
+  maven_repo = https://repo1.maven.org/maven2
+  in_build = true