Updates the examples to use the new build scripts (except Hula). (#74)

* Added Makefile and topology.jsons for all examples.

* use branch

* Updated MRI exercise (#73)

* Updated MRI exercise

* Updated basic_tunnel.p4 for changes to p4 lang

* updated other examples

P4D2_2017_Fall/exercises/basic_tunnel/topology.json

@@ -0,0 +1,16 @@
+{
+    "hosts": [
+        "h1",
+        "h2",
+        "h3"
+    ],
+    "switches": {
+        "s1": { "cli_input" : "s1-commands.txt" },
+        "s2": { "cli_input" : "s2-commands.txt" },
+        "s3": { "cli_input" : "s3-commands.txt" }
+    },
+    "links": [
+        ["h1", "s1"], ["s1", "s2"], ["s1", "s3"], 
+        ["s3", "s2"], ["s2", "h2"], ["s3", "h3"]
+    ]
+}