Update libjuju

- fix licensing quirks
- refresh against libjuju master

Signed-off-by: Adam Israel <adam.israel@canonical.com>
diff --git a/modules/libjuju/juju/client/client.py b/modules/libjuju/juju/client/client.py
index 89b5248..2f3e49d 100644
--- a/modules/libjuju/juju/client/client.py
+++ b/modules/libjuju/juju/client/client.py
@@ -5,7 +5,7 @@
 
 
 for o in overrides.__all__:
-    if not "Facade" in o:
+    if "Facade" not in o:
         # Override stuff in _definitions, which is all imported
         # into _client. We Monkey patch both the original class and
         # the ref in _client (import shenanigans are fun!)