MAINT: Fix syntax of .travis.yml
diff --git a/.travis.yml b/.travis.yml
index a473417..ee1d3fd 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -12,6 +12,7 @@
       env:
       - ALL=' '
     - rust: 1.15.0
+      env:
       - ALL=' '
     - rust: stable
       env: