Hotfix for QIIME_CONFIG_FP env var

This variable is being set twice by qiime-deploy after https://github.com/qiime/qiime-deploy/pull/56 was merged. New strategy is to have qiime-deploy set the env var.
Merge pull request #100 from jrrideout/qiime-config-fp-fix

Hotfix for QIIME_CONFIG_FP env var