Fixed issue with alpha branch by installing additional dependency.

Signed-off-by: Niklas Voss <niklas.voss@gmail.com>

Author: trevex

Dockerfile

@@ -2,7 +2,7 @@ FROM ubuntu:17.10 as BUILD
 MAINTAINER source{d}
 
 RUN apt-get -y update && \
-    apt-get -y install curl git bc make dpkg-dev libssl-dev module-init-tools p7zip-full libelf-dev && \
+    apt-get -y install curl git bc make dpkg-dev libssl-dev module-init-tools p7zip-full libelf-dev flex bison && \
     apt-get autoremove && \
     apt-get clean