Fix deprecated go get command issue in assets-in-binary README. (gin-…

…gonic#132)

assets-in-binary/example01/README.md

@@ -11,7 +11,7 @@ This is a complete example to create a single binary with the
 
 ```sh
 go get github.com/gin-gonic/gin
-go get github.com/jessevdk/go-assets-builder
+go install github.com/jessevdk/go-assets-builder@latest
 ```
 
 ### Generate assets.go