More code style cleanup

Clean up a few more unnecessary usages of lambda in `repo` that were missed
in the previous sweep that only considered files ending in .py.

Remove a duplicate import.

Change-Id: I03cf467a5630cbe4eee6649520c52e94a7db76be
diff --git a/main.py b/main.py
index f41fb80..9fbccfb 100755
--- a/main.py
+++ b/main.py
@@ -28,7 +28,6 @@
   import urllib.request
 else:
   # For python2
-  import imp
   urllib = imp.new_module('urllib')
   urllib.request = urllib2
 
diff --git a/repo b/repo
index 96302c0..e06a5d5 100755
--- a/repo
+++ b/repo
@@ -275,9 +275,9 @@
     raise CloneFailure()
 
   ver_str = ver_str[len('git version '):].strip()
-  ver_act = tuple(map(lambda x: int(x), ver_str.split('.')[0:3]))
+  ver_act = tuple(map(int, ver_str.split('.')[0:3]))
   if ver_act < MIN_GIT_VERSION:
-    need = '.'.join(map(lambda x: str(x), MIN_GIT_VERSION))
+    need = '.'.join(map(str, MIN_GIT_VERSION))
     print >>sys.stderr, 'fatal: git %s or later required' % need
     raise CloneFailure()
 
@@ -294,7 +294,7 @@
   if not kv:
     return True
 
-  kv = tuple(map(lambda x: int(x), kv.split('.')))
+  kv = tuple(map(int, kv.split('.')))
   if kv < KEYRING_VERSION:
     return True
   return False
@@ -343,7 +343,7 @@
   print
 
   fd = open(os.path.join(home_dot_repo, 'keyring-version'), 'w')
-  fd.write('.'.join(map(lambda x: str(x), KEYRING_VERSION)) + '\n')
+  fd.write('.'.join(map(str, KEYRING_VERSION)) + '\n')
   fd.close()
   return True
 
@@ -725,7 +725,7 @@
   if my_main:
     repo_main = my_main
 
-  ver_str = '.'.join(map(lambda x: str(x), VERSION))
+  ver_str = '.'.join(map(str, VERSION))
   me = [repo_main,
         '--repo-dir=%s' % rel_repo_dir,
         '--wrapper-version=%s' % ver_str,