Create a plugin for up'ing a lo device

- Believe we need sudo to create netns
- Use syscall instead of relying on ip netns
- Add sudo to .travis.yml
- Needs more -E
- Revert Godeps GoVersion to 1.4.2
- in travis, test command is run with all necessary env vars
- Loopback plugin only works on 'lo' interface
- Update README, add loopback plugin config
- note script dependency on jq

Signed-off-by: Gabe Rosenhouse <grosenhouse@pivotal.io>

.travis.yml

@@ -1,4 +1,5 @@
 language: go
+sudo: required
 
 go:
   - 1.4
@@ -12,4 +13,7 @@ install:
  - go get ${TOOLS_CMD}/vet
 
 script:
- - ./test
+ - sudo -E /bin/bash -c 'PATH=$GOROOT/bin:$PATH ./test'
+
+notifications:
+  email: false