Merge pull request #23 from hashicorp/go-mod-tidy

Fix failing tests
diff --git a/.travis.yml b/.travis.yml
index 304a835..24b8038 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -9,4 +9,4 @@
   only:
     - master
 
-script: make test testrace
+script: env GO111MODULE=on make test testrace
diff --git a/go.sum b/go.sum
index 85b1f8f..e8238e9 100644
--- a/go.sum
+++ b/go.sum
@@ -1,4 +1,2 @@
-github.com/hashicorp/errwrap v0.0.0-20141028054710-7554cd9344ce h1:prjrVgOk2Yg6w+PflHoszQNLTUh4kaByUcEWM/9uin4=
-github.com/hashicorp/errwrap v0.0.0-20141028054710-7554cd9344ce/go.mod h1:YH+1FKiLXxHSkmPseP+kNlulaMuP3n2brvKWEqk/Jc4=
 github.com/hashicorp/errwrap v1.0.0 h1:hLrqtEDnRye3+sgx6z4qVLNuviH3MR5aQ0ykNJa/UYA=
 github.com/hashicorp/errwrap v1.0.0/go.mod h1:YH+1FKiLXxHSkmPseP+kNlulaMuP3n2brvKWEqk/Jc4=