try adding files relative

Apparently `git add -A` doesn’t traverse up to parent directories on
old versions of git, causing this to not add the files on travis-ci.
See if this is an acceptable workaround.

features/command_status.feature

@@ -102,7 +102,7 @@ Feature: status command
  <abspath_end>
  """
  # STAGED 'NEW FILE' CHANGES
- Given I successfully run `git add -A`
+ Given I successfully run `git add "<displaypath>"`
  When I successfully run `scmpuff status`
  Then the stdout from "scmpuff status" should contain:
  """