update build.sh to use vendor

build.sh

@@ -59,7 +59,10 @@ if [ "x$ipfs" == "xyes" ] ; then
     echo "obtaining gx"
     go get -v github.com/whyrusleeping/gx
     go get -v github.com/whyrusleeping/gx-go
+    mkdir -p vendor/gx/ipfs
+    cd vendor/gx/ipfs
     gx get $rev
+    cd $root
     go get -u -v gx/ipfs/$rev/srndv2
 else
     go get -u -v github.com/majestrate/srndv2