Improved Primitive support and better testing

This changeset addresses several issues.

- Improve primitive support so the status and output of an executed
primitive can be retrieved
- Merge latest upstream libjuju (required for new primive features)
- New testing framework
    This is the start of a new testing framework with the ability to
create and configure LXD containers with SSH, to use while testing proxy
charms.
- Add support for using ssh keys with proxy charms
    See Feature 1429. This uses the per-proxy charm/unit ssh keypair

Signed-off-by: Adam Israel <adam.israel@canonical.com>
diff --git a/modules/libjuju/tests/unit/test_constraints.py b/modules/libjuju/tests/unit/test_constraints.py
index 00b9156..3c52090 100644
--- a/modules/libjuju/tests/unit/test_constraints.py
+++ b/modules/libjuju/tests/unit/test_constraints.py
@@ -32,6 +32,12 @@
         self.assertEqual(_("10G"), 10 * 1024)
         self.assertEqual(_("10M"), 10)
         self.assertEqual(_("10"), 10)
+        self.assertEqual(_("foo,bar"), "foo,bar")
+
+    def test_normalize_list_val(self):
+        _ = constraints.normalize_list_value
+
+        self.assertEqual(_("foo"), ["foo"])
         self.assertEqual(_("foo,bar"), ["foo", "bar"])
 
     def test_parse_constraints(self):
@@ -43,6 +49,9 @@
         )
 
         self.assertEqual(
-            _("mem=10G foo=bar,baz"),
-            {"mem": 10 * 1024, "foo": ["bar", "baz"]}
+            _("mem=10G foo=bar,baz tags=tag1 spaces=space1,space2"),
+            {"mem": 10 * 1024,
+             "foo": "bar,baz",
+             "tags": ["tag1"],
+             "spaces": ["space1", "space2"]}
         )