Travis update

use default ES install (1.3.4 atm)
use go 1.3 (1.3.3 atm)
Misc (Go style) cleanups.

Should be no functional change
Queuesize can be either '"1k"' or -1. Really.

At least on my 1.4.1 ES.
This could use a better fix, with a custom JSON decoder.
Don't use globals which are shared among tests.
Fix TestBulkIndexerBasic

- don't format the date. This depends on the timezone of the test install (and
  were the case of off-by-5 errors on Travis)
- Delete the index at the start of the test run.
Be more liberal with refreshes.

No idea if this actually fixes things, but it won't hurt.
Be more relaxed about the cluster name.
Merge pull request #145 from alicebob/tests

Travis builds