Update to new module-ci that installs Go 1.7.3

Go 1.6.x doesn’t work with the latest version of OS X
(https://golang.org/doc/go1.7#ports), so this update will hopefully fix
#41.

circle.yml

@@ -6,7 +6,7 @@ dependencies:
   override:
     # Install the gruntwork-module-circleci-helpers and use it to configure the build environment and run tests.
     - curl -Ls https://raw.githubusercontent.com/gruntwork-io/gruntwork-installer/master/bootstrap-gruntwork-installer.sh | bash /dev/stdin --version 0.0.13
-    - gruntwork-install --module-name "gruntwork-module-circleci-helpers" --repo "https://github.com/gruntwork-io/module-ci" --tag "v0.0.25"
+    - gruntwork-install --module-name "gruntwork-module-circleci-helpers" --repo "https://github.com/gruntwork-io/module-ci" --tag "v0.2.0"
     - configure-environment-for-gruntwork-module --packer-version NONE --terragrunt-version NONE --go-src-path .
 
   cache_directories: