Fix docker build job. Use 'go' command inside the Dockerfile.
Bump version to 1.0.4

Change-Id: I313943a945f237819f95cd922526f4f0333c11f0
diff --git a/docker/Dockerfile b/docker/Dockerfile
index 86cf348..96d3c5b 100644
--- a/docker/Dockerfile
+++ b/docker/Dockerfile
@@ -27,7 +27,7 @@
 # Build openolt
 SHELL ["/bin/ash", "-o", "pipefail", "-c"]
 ENV GO111MODULE=on
-RUN go build -mod=vendor -o /go/bin/openolt-scale-tester
+RUN  go mod vendor && go build -mod=vendor && go build -mod=vendor -o /go/bin/openolt-scale-tester
 
 # -------------
 # Image creation stage