Move unittest YAML files into their own directory, pending more python unit tests in a followup commit

unittest/yaml/error-bridgedomain3.yaml

@@ -0,0 +1,22 @@
+test:
+  description: "Interfaces put into the bridge, can't be L3 (so cannot have an address)"
+  errors:
+    expected:
+     - "interface .* has an address but no LCP"
+     - "sub-interface .* has an address but .* does not have LCP"
+     - "bridgedomain .* member .* has an address"
+    count: 6
+---
+interfaces:
+  GigabitEthernet1/0/0:
+    addresses: [ 192.0.2.1/29 ]
+  GigabitEthernet2/0/0:
+    addresses: [ 192.0.2.9/29 ]
+    sub-interfaces:
+      101:
+        addresses: [ 192.0.2.17/29 ]
+
+bridgedomains:
+  bd10:
+    description: "Bridge Domain 10"
+    interfaces: [ GigabitEthernet1/0/0, GigabitEthernet2/0/0, GigabitEthernet2/0/0.101 ]