Update Dockerfile: Update gcc, g++ & gfortan to verison 9 and update to OpenMPI 4

Dockerfile

 FROM opensuse/leap:latest
-RUN zypper install -y git \
+RUN zypper ar -f -n OSS http://download.opensuse.org/distribution/leap/15.2/repo/oss/ OSS \
+ && zypper install -y git \
  && zypper install -y unzip \
  && zypper install -y gzip \
  && zypper install -y -t pattern devel_basis devel_C_C++ devel_java \
  && zypper install -y python curl \
  && zypper install -y boost-devel cmake cgal-devel lcov \
- && zypper install -y gcc7-c++ gcc-fortran \
- && zypper ar -f -n OSS http://download.opensuse.org/distribution/leap/15.2/repo/oss/ OSS \
- && zypper install -y gcc8 gcc8-c++ gcc8-fortran \
  && zypper install -y gcc9 gcc9-c++ gcc9-fortran \
  && zypper install -y libqt5-qtbase-devel \
  && zypper install -y wget \
  && zypper install -y doxygen \
- && zypper install -y openmpi3-devel \
+ && zypper install -y openmpi4-devel \
  && zypper install -y openblas-devel openblas-devel-headers \
  && zypper install -y libopenblas_pthreads0 libopenblas_pthreads-devel \
- && update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-7 7 \
- && update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-7 7 \
- && update-alternatives --install /usr/bin/gfortran gfortran /usr/bin/gfortran-7 7 \
- && update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-8 8 \
- && update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-8 8 \
- && update-alternatives --install /usr/bin/gfortran gfortran /usr/bin/gfortran-8 8 \
  && update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-9 9 \
  && update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-9 9 \
  && update-alternatives --install /usr/bin/gfortran gfortran /usr/bin/gfortran-9 9 
 
-
-
 # Define the ENTRYPOINT for subsequent commands (CMD)
 ENTRYPOINT ["/bin/bash", "-l", "-c"]
 # SHELL defines which login shell will be used within RUN steps
@@ -35,4 +25,4 @@ SHELL ["/bin/bash", "-l", "-c"]
 CMD ["bash"]
 
 # Source MPI environment script
-RUN echo "source /usr/lib64/mpi/gcc/openmpi3/bin/mpivars.sh" >> /etc/bash.bashrc
+RUN echo "source /usr/lib64/mpi/gcc/openmpi4/bin/mpivars.sh" >> /etc/bash.bashrc