[GinR] Travis build deps

.travis.yml

@@ -1,6 +1,5 @@
 language: go
 go:
-  - 1.6
   - 1.7
   - 1.8
   - master
@@ -13,6 +12,7 @@ env:
   - GO15VENDOREXPERIMENT=1
 
 script:
+  - go get github.com/docopt/docopt-go
   - go get github.com/G-Node/gin-doi/src
   - go get gopkg.in/yaml.v2
   - go get github.com/G-Node/gin-dex/gindex