htseq: fix Dockerfile

src/docker_modules/htseq/0.8.0/Dockerfile

@@ -3,11 +3,11 @@ FROM ubuntu:18.04
 MAINTAINER Laurent Modolo
 
 ENV HTSEQ_VERSION=0.8.0
-ENV PACKAGES build-essential=12.4* \
-             python3-pip=9.0.1* \
-             python3-setuptools=39.0.1* \
-             python3-dev=3.6.5* \
-             python3-wheel=0.30.0*
+ENV PACKAGES build-essential \
+             python3-pip \
+             python3-setuptools \
+             python3-dev \
+             python3-wheel
 
 RUN apt-get update && \
     apt-get install -y --no-install-recommends ${PACKAGES} && \