Bump vcap_staging

git shortlog a7fb8242..b853f5d6
Bleicke and Jennifer Hickey (4):
      Allow multiple database services for all buildpack apps but Rails
      Merge "Allow multiple database services for all buildpack
        apps but Rails"
      Set vcap_logging dependency version to 0.1.4
      Merge "Set vcap_logging dependency version to 0.1.4

Change-Id: I8208fcb73735c0880495d137cbe84962b84ce05f