Add postgres build and allow it to fail.

refs #1333
Issue #1556 - Fix meta_title is undefined

Closes #1556 and #1530

This should also fix meta_description in #1530 as well as the other bug that is not
filed for body_class
Fix failing casper tests

no issue
- spam test: changed waitForSelector to waitForText
- feature test: changed waitForRessource to watiForSelector
Merge pull request #1559 from sebgie/failing-tests

Fix failing casper tests
Putting back relative redirects

issue #1523

- also added some comments to indicate the difference between the two custom middleware files.
Merge pull request #1557 from alicoding/issue1556

Issue #1556 - Fix meta_title is undefined
Create the config module, initially used
to standardise getting paths and absolute URLs.  Easy
to extend for other configurations we may need.
Merge pull request #1565 from ErisDS/redirect-fixes

Putting back relative redirects
Merge pull request #1535 from hswolff/create-config-module

Create config module to standardise getting paths and abs URLs
Merge pull request #1555 from halfdan/1333-allowed-failure

Add postgres build and allow it to fail.
Merge branch 'master' of github.com:TryGhost/Ghost

* 'master' of github.com:TryGhost/Ghost:
  Create the config module, initially used to standardise getting paths and absolute URLs.  Easy to extend for other configurations we may need.
  Putting back relative redirects
  Fix failing casper tests
  Issue #1556 - Fix meta_title is undefined
  Add postgres build and allow it to fail.