Update readme.
Travis must not rely on tags
Merge pull request #7 from go-pg/feature/travis

Travis must always test current branch, not gopkg.in/pg.v1
Fix NULL decoding. Fixes #8.
Merge pull request #9 from go-pg/fix/null_decoding2

Fix NULL decoding. Fixes #8.
Encode time in local timezone. Decode time without timezone in local timezone.