Buck: Adjust to unflattened directory structure for python libraries

Since this Buck's commit 59759043f66de17140b423a7f11a2d8827b4cbbf the whole
unflattened subtree is used.

Change-Id: I4ec930a452d4867add3f5dd46430d3184c2a7277

tools/BUCK

@@ -14,7 +14,10 @@ python_binary(
 
 python_library(
   name = 'util',
-  srcs = ['util.py'],
+  srcs = [
+    'util.py',
+    '__init__.py'
+  ],
   visibility = ['PUBLIC'],
 )
 

tools/maven/mvn.py

@@ -16,8 +16,9 @@
 from __future__ import print_function
 from optparse import OptionParser
 from os import path
+
 from sys import stderr
-from util import check_output
+from tools.util import check_output
 
 opts = OptionParser()
 opts.add_option('--repository', help='maven repository id')