build: upgrade to Go 1.13.x

adamdecaf · adamdecaf · commit aac5c96317b3 · 2020-01-14T15:43:56.000-06:00
diff --git a/.travis.yml b/.travis.yml
@@ -6,11 +6,8 @@ os:
   - osx
 
 go:
-  - 1.9.x
-  - 1.10.x
-  - 1.11.x
-
-osx_image: xcode9.1
+  - 1.12.x
+  - 1.13.x
 
 matrix:
   fast_finish: true
