geocouch tag couchdb1.3.x

Without this it does not compile.

```
balrog:Formula n$ brew install geocouch
==> Cloning https://github.com/couchbase/geocouch.git
Updating /Library/Caches/Homebrew/geocouch--git
==> Checking out tag couchdb1.3.x
==> Downloading http://www.apache.org/dyn/closer.cgi?path=/couchdb/source/1.6.0/apache-couchdb-1.6.0.tar.gz
Already downloaded: /Library/Caches/Homebrew/couchdb-1.6.0.tar.gz
==> make
fatal: Not a git repository (or any of the parent directories): .git
make: erl: Command not found
ERL_COMPILER_OPTIONS='' ./rebar compile
env: escript: No such file or directory
make: *** [compile] Error 127
```