Update Go versions in Travis

* Updated the versions of Go we run on to reflect our support protocol

Author: boyan-soubachov

.travis.yml

@@ -4,18 +4,14 @@ os: linux
 jobs:
   include:
     - go: "1.10.x"
-    - go: "1.11.x"
-      env: GO111MODULE=off
-    - go: "1.11.x"
-      env: GO111MODULE=on
-    - go: "1.12.x"
-      env: GO111MODULE=off
-    - go: "1.12.x"
-      env: GO111MODULE=on
     - go: "1.13.x"
       env: GO111MODULE=off
     - go: "1.13.x"
       env: GO111MODULE=on
+    - go: "1.14.x"
+      env: GO111MODULE=off
+    - go: "1.14.x"
+      env: GO111MODULE=on
     - go: master
       env: GO111MODULE=on
     - go: master