inconsistency: wsk project does not respect WSK_CONFIG_FILE

Wtih the `wskdeploy` integration, doing `WSK_CONFIG_FILE=/Users/anthony/.wskprops-iks wsk project deploy` does not use the config file set in the environment variable. `wsk project deploy` will use the wskprops in the default location `~/.wskprops`.

Workaround is to use `wsk project deploy --config ` which is similar to what wskdeploy uses.

Having 2 ways to set the config file can be confusing: "Use `WSK_CONFIG_FILE` env to specify location of wskprops and use `--config` when using wsk project commands"

Related Issue: https://github.com/apache/incubator-openwhisk-wskdeploy/issues/809