P4 Developer Day May 2019 (#252)

* Update user-bootstrap to use latest version (#251)

* p4c tests are failing in latest version. So, let's skip it during vagrant provisioning

* Update tutorial to use latest version of P4 tools

Modify switch.py to handle setting default_action
Use --p4runtime-files instead of deprecated --p4runtime-file and
--p4runtime-format flags
Provide standard_metadata for mark_to_drop

* Fix path for ECN exercise

exercises/ecn/s1-runtime.json

@@ -0,0 +1,52 @@
+{
+  "target": "bmv2",
+  "p4info": "build/ecn.p4.p4info.txt",
+  "bmv2_json": "build/ecn.json",
+  "table_entries": [
+    {
+      "table": "MyIngress.ipv4_lpm",
+      "match": {
+        "hdr.ipv4.dstAddr": ["10.0.1.1", 32]
+      },
+      "action_name": "MyIngress.ipv4_forward",
+      "action_params": {
+        "dstAddr": "00:00:00:00:01:01",
+        "port": 2
+      }
+    },
+    {
+      "table": "MyIngress.ipv4_lpm",
+      "match": {
+        "hdr.ipv4.dstAddr": ["10.0.1.11", 32]
+      },
+      "action_name": "MyIngress.ipv4_forward",
+      "action_params": {
+        "dstAddr": "00:00:00:00:01:0b",
+        "port": 1
+      }
+    },
+ 
+    {
+      "table": "MyIngress.ipv4_lpm",
+      "match": {
+        "hdr.ipv4.dstAddr": ["10.0.2.0", 24]
+      },
+      "action_name": "MyIngress.ipv4_forward",
+      "action_params": {
+        "dstAddr": "00:00:00:02:03:00",
+        "port": 3
+      }
+    },
+    {
+      "table": "MyIngress.ipv4_lpm",
+      "match": {
+        "hdr.ipv4.dstAddr": ["10.0.3.0", 24]
+      },
+      "action_name": "MyIngress.ipv4_forward",
+      "action_params": {
+        "dstAddr": "00:00:00:03:02:00",
+        "port": 4
+      }
+    }
+  ]
+}