upgrade to v1.8

.travis.yml

@@ -13,5 +13,5 @@ install:
   - go get github.com/goanywhere/cmd
 
 go:
-  - 1.7
+  - 1.8
   - tip

README.md

@@ -9,6 +9,7 @@ Rex is a library for modular web development in [Go](http://golang.org/), design
 - [X] v1.5
 - [X] v1.6
 - [X] v1.7
+- [X] v1.8
 
 
 ## Intro