travis: Set GO111MODULE=on for mage install

See #5115

diff --git a/.travis.yml b/.travis.yml
index 7058711beddbbea9d1a9276dcd5118de62d76dbc..7c2948f49d03698b024875bc8f4d0d16ac46ae1f 100644 (file)
--- a/.travis.yml
+++ b/.travis.yml
@@ -16,9 +16,8 @@ matrix:
     - go: tip
   fast_finish: true
 install:
-  - go get github.com/magefile/mage
-  - mage -v vendor
-script:
+  - env GO111MODULE=on go get github.com/magefile/mage
+ script:
   - mage -v test
   - mage -v check
   - mage -v hugo