[#75804242] Consolidate documentation on how to run the tests

Make our documentation consistent so that we only document one way of running the tests.

Do this by replacing the Makefile with a stub bash script and update the Travis CI configuration accordingly.
I think it has, comparing the output:
```
➜  cdn-acceptance-tests git:(master) ✗ go test -edgeHost 172.16.20.10 -skipVerifyTLS -skipFailover -v
2014/08/21 16:07:56 Confirming that CDN is healthy
2014/08/21 16:07:56 Started server on port 8080
2014/08/21 16:07:56 Checking health of origin...
^C%
```
```
➜  cdn-acceptance-tests git:(75804242-consolidate-docs) ✗ go test -edgeHost 172.16.20.10 -skipVerifyTLS -skipFailover -v
=== RUN TestCacheFirstResponse
2014/08/21 16:08:07 Started server on port 8080
2014/08/21 16:08:07 Checking health of origin...
^C%
```