Change the version to 2.0.0

It's time to get some more folks using this. I'm sure they will be
finding more things to fix.

Signed-off-by: Konstantin Ryabitsev <konstantin@linuxfoundation.org>
diff --git a/grokmirror/__init__.py b/grokmirror/__init__.py
index 3189ff6..338640a 100644
--- a/grokmirror/__init__.py
+++ b/grokmirror/__init__.py
@@ -38,9 +38,9 @@
 from requests.packages.urllib3.util.retry import Retry
 
 
-VERSION = '2.0-dev'
+VERSION = '2.0.0'
 MANIFEST_LOCKH = None
-REPO_LOCKH = {}
+REPO_LOCKH = dict()
 GITBIN = '/usr/bin/git'
 
 # default logger. Will be overridden.
@@ -815,7 +815,7 @@
 
     if not os.path.exists(manifile):
         logger.info(' manifest: no local manifest, assuming initial run')
-        return {}
+        return dict()
 
     if manifile.find('.gz') > 0:
         fh = gzip.open(manifile, 'rb')