Fix running travis on forked repos

If we're not on the official repo, link the directory structure around
so that go can still find the code.

.travis.fix-fork.sh

@@ -0,0 +1,9 @@
+#!/bin/bash
+
+if echo $TRAVIS_BUILD_DIR | grep -vq "github.com/google/blueprint$" ; then
+  cd ../..
+  mkdir -p google
+  mv $TRAVIS_BUILD_DIR google/blueprint
+  cd google/blueprint
+  export TRAVIS_BUILD_DIR=$PWD
+fi

.travis.yml

@@ -3,6 +3,9 @@ language: go
 install:
     - sudo apt-get install ninja-build
 
+before_script:
+    - source .travis.fix-fork.sh
+
 script:
     - go test ./...
     - cp build.ninja.in build.ninja.in.orig