Bump docker base image to 1.8.3

added also new dependencies used in the new makefile

Signed-off-by: Flavio Crisciani <flavio.crisciani@docker.com>

libnetwork/Dockerfile.build

@@ -1,7 +1,9 @@
-FROM golang:1.7.1
+FROM golang:1.8.3
 RUN apt-get update && apt-get -y install iptables
 
 RUN go get github.com/tools/godep \
 		github.com/golang/lint/golint \
-		golang.org/x/tools/cmd/cover\
-		github.com/mattn/goveralls
+		golang.org/x/tools/cmd/cover \
+		github.com/mattn/goveralls \
+		github.com/gordonklaus/ineffassign \
+		github.com/client9/misspell/cmd/misspell