This update provides:
1)  workaround around the build failures. In
summary, it forces the download of some packages during the build
process.
2) update the set of packages that should go inside the vendor
directory
3) Update the dockerfile to use go 1.10

Change-Id: I2bfd090ce0f25b0c10aa214755ae2da7e5384d60
diff --git a/Gopkg.toml b/Gopkg.toml
index e2a92b0..3b2efd2 100644
--- a/Gopkg.toml
+++ b/Gopkg.toml
@@ -107,11 +107,11 @@
   name = "go.uber.org/zap"
   version = "1.9.1"
 
-[[constraint]]
+[[override]]
   branch = "master"
   name = "golang.org/x/net"
 
-[[constraint]]
+[[override]]
   branch = "master"
   name = "google.golang.org/genproto"