Update travis docs deployment to properly deploy v*.*.* branches

Tiny change in the travis file, deployed! https://travis-ci.org/YeoLab/flotilla/builds/40397004#L1578

Need to also update the `git push` behavior before merged

```
warning: push.default is unset; its implicit value is changing in
Git 2.0 from 'matching' to 'simple'. To squelch this message
and maintain the current behavior after the default changes, use:
  git config --global push.default matching
To squelch this message and adopt the new behavior now, use:
  git config --global push.default simple
See 'git help config' and search for 'push.default' for further information.
(the 'simple' mode was introduced in Git 1.7.11. Use the similar mode
'current' instead of 'simple' if you sometimes use older versions of Git)
```