added build-essential dep to dockerfiles (#3666)

docker/ubuntu-stable/Dockerfile

@@ -3,6 +3,7 @@ WORKDIR /build
 # install tools and dependencies
 RUN apt-get update && \
         apt-get install -y \
+        build-essential \
         g++ \
         curl \
         git \

docker/ubuntu/Dockerfile

@@ -4,6 +4,7 @@ WORKDIR /build
 RUN apt-get update && \
         apt-get install -y \
         g++ \
+        build-essential \
         curl \
         git \
         file \