ENV_DIR requires an absolute path

[zmb3]

I ran the script with ENV_DIR=env1 and was greeted with:

~/gcp-pcf-quickstart/src/omg-tf ~/gcp-pcf-quickstart
loading environment config: open env1/config.json: no such file or directory

I am certain that the env1/config.json file exists at this relative path.

If I rerun with ENV_DIR=/Users/me/gcp-pcf-quickstart/env1 everything works.

[zmb3]

Looks like this happens because the deploy script changes into the ENV_DIR's terraform directory and then runs omg-cli commands.

Might be best just to add a note to the help message and/or README, as checking for relative paths in bash in a portable manner is somewhat nasty.