Upgrade to Insta master to get bugfix.

Map sorting in Insta was previously not recursive.
As of this PR, it is!
https://github.com/mitsuhiko/insta/pull/80

Since it hasn't made it into a release yet, but is
important for Rojo to have snapshot determinism,
we're moving temporarily to depend on Insta via Git.

rojo-test/serve-test-snapshots/serve_test__scripts_subscribe.snap

@@ -1,18 +1,18 @@
 ---
 source: rojo-test/src/serve_test.rs
-expression: redactions.redacted_yaml(subscribe_response)
+expression: "subscribe_response.intern_and_redact(&mut redactions, ())"
 ---
 messageCursor: 1
 messages:
-  - removedInstances: []
-    addedInstances: {}
+  - addedInstances: {}
+    removedInstances: []
     updatedInstances:
-      - id: id-4
+      - changedClassName: ~
+        changedMetadata: ~
         changedName: ~
-        changedClassName: ~
         changedProperties:
           Source:
             Type: String
             Value: Updated foo!
-        changedMetadata: ~
+        id: id-4
 sessionId: id-1