api: Don't require 'https://' in site option.

The --site= option is really only for internal developer use, so I
don't think we gain anything from being strict about it.

(And it doesn't help that the error message one gets pre-this-patch is
super confusing).  Fixes Trac #937.

(imported from commit 8d699982aa6830f9eae2bccd6d0c7a1e0e53dd56)

humbug/__init__.py

@@ -90,6 +90,8 @@ class Client(object):
         self.email = email
         self.verbose = verbose
         if site is not None:
+            if not site.startswith("http"):
+                site = "https://" + site
             self.base_url = site
         else:
             self.base_url = "https://humbughq.com"