Merge pull request #66 from hashicorp/update-circle-config-save-cache

update circle config to save go mod cache
diff --git a/.circleci/config.yml b/.circleci/config.yml
index 11d5035..7289c6b 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -25,6 +25,8 @@
           keys:
             - go-version-modcache-v1-{{ checksum "go.mod" }}
 
+      - run: go mod download
+
       # Save go module cache if the go.mod file has changed
       - save_cache:
           key: go-version-modcache-v1-{{ checksum "go.mod" }}