travis: updates

fix golint url and add newer golang versions

Signed-off-by: Vincent Batts <vbatts@hashbangbash.com>

.travis.yml

@@ -1,16 +1,17 @@
 language: go
 go:
   - 1.x
+  - 1.11.x
+  - 1.10.x
   - 1.9.x
   - 1.8.x
   - 1.7.x
-  - 1.6.x
 
 sudo: false
 
 before_install:
   - git config --global url."https://".insteadOf git://
-  - go get -u github.com/golang/lint/golint
+  - go get -u -v golang.org/x/lint/golint
   - mkdir -p $GOPATH/src/github.com/emojisum && ln -sf $(pwd) $GOPATH/src/github.com/emojisum/emojisum
   - go get -d ./...