Use strings for Go versions

YAML sees these as numbers so 1.10 is seen as 1.1 which is not the version we want to target.
hooklift · Feb 1, 2019 · 199b101 · 199b101
1 parent ac769a6
commit 199b101
Showing 1 changed file with 3 additions and 3 deletions.
diff --git a/.travis.yml b/.travis.yml
@@ -1,9 +1,9 @@
 language: go
 
 go:
-  - 1.10
-  - 1.11
-  - tip
+  - "1.10"
+  - "1.11"
+  - "tip"
 
 matrix:
   allow_failures: