Update the Travis and CircleCI Go versions (spf13#651)

Author: michael-k

.circleci/config.yml

@@ -26,11 +26,11 @@ version: 2
 jobs:
   go-current:
     docker:
-      - image: circleci/golang:1.8.3
+      - image: circleci/golang:1.10.0
     <<: *base
   go-previous:
     docker:
-      - image: circleci/golang:1.7.6
+      - image: circleci/golang:1.9.4
     <<: *base
   go-latest:
     docker:

.travis.yml

@@ -2,8 +2,8 @@ language: go
 
 matrix:
   include:
-    - go: 1.7.6
-    - go: 1.8.3
+    - go: 1.9.4
+    - go: 1.10.0
     - go: tip
   allow_failures:
     - go: tip