chore(rootfs/Dockerfile): upgrade to Go 1.6

Aaron Schlesinger · Aaron Schlesinger · commit 050f497688b3 · 2016-02-18T08:13:21.000-08:00
diff --git a/rootfs/Dockerfile b/rootfs/Dockerfile
@@ -1,4 +1,4 @@
-FROM golang:1.5.1
+FROM golang:1.6.0
 
 ENV GO15VENDOREXPERIMENT=1
 ENV GLIDE_HOME=/root
