Merge pull request #1 from thebaron/master

Updates to paas-skeleton
Merge pull request #2 from thebaron/master

Add LD_LIBRARY_PATH for postgres to environment.sh
Add support for PIP_EXTRAS manually ordered dependencies

- Use mirrors for pypi downloads
- Use a download cache for downloads
Add better pip download cache support, fix scl references
Fix exit call syntax, include missing deps
Added Specification Template document.