Add Imgur rate limiting

lib/ratelimit/version.py

@@ -0,0 +1,9 @@
+class Version(object):
+    '''Version of the package'''
+
+    def __setattr__(self, *args):
+        raise TypeError('cannot modify immutable instance')
+    __delattr__ = __setattr__
+
+    def __init__(self, num):
+        super(Version, self).__setattr__('number', num)