Add Antelope, Bobcat and Caracal releases to versionutils

Now that we have names for the next release we can get it
added here so we'll be ready when development starts.

Also adding previous series names. They were missing.

Change-Id: I2a9a2ab4b03e7d6b804a375c877c2c632df11945

oslo_log/versionutils.py

@@ -78,6 +78,9 @@ _RELEASES = {
     'X': 'Xena',
     'Y': 'Yoga',
     'Z': 'Zed',
+    'A': 'Antelope',
+    'B': 'Bobcat',
+    'C': 'Caracal',
 }
 
 
@@ -161,6 +164,9 @@ class deprecated(object):
     XENA = 'X'
     YOGA = 'Y'
     ZED = 'Z'
+    ANTELOPE = 'A'
+    BOBCAT = 'B'
+    CARACAL = 'C'
 
     def __init__(self, as_of, in_favor_of=None, remove_in=2, what=None):
         """Initialize decorator