THRIFT-3596 Better conformance to PEP8

This closes #832
diff --git a/lib/py/src/TSCons.py b/lib/py/src/TSCons.py
index ed2601a..bc67d70 100644
--- a/lib/py/src/TSCons.py
+++ b/lib/py/src/TSCons.py
@@ -20,18 +20,17 @@
 from os import path
 from SCons.Builder import Builder
 from six.moves import map
-from six.moves import zip
 
 
 def scons_env(env, add=''):
-  opath = path.dirname(path.abspath('$TARGET'))
-  lstr = 'thrift --gen cpp -o ' + opath + ' ' + add + ' $SOURCE'
-  cppbuild = Builder(action=lstr)
-  env.Append(BUILDERS={'ThriftCpp': cppbuild})
+    opath = path.dirname(path.abspath('$TARGET'))
+    lstr = 'thrift --gen cpp -o ' + opath + ' ' + add + ' $SOURCE'
+    cppbuild = Builder(action=lstr)
+    env.Append(BUILDERS={'ThriftCpp': cppbuild})
 
 
 def gen_cpp(env, dir, file):
-  scons_env(env)
-  suffixes = ['_types.h', '_types.cpp']
-  targets = map(lambda s: 'gen-cpp/' + file + s, suffixes)
-  return env.ThriftCpp(targets, dir + file + '.thrift')
+    scons_env(env)
+    suffixes = ['_types.h', '_types.cpp']
+    targets = map(lambda s: 'gen-cpp/' + file + s, suffixes)
+    return env.ThriftCpp(targets, dir + file + '.thrift')