Install pip via apt

adapters/Dockerfile.fenics-adapter

@@ -14,21 +14,20 @@ RUN apt-get -qq update && apt-get -qq install \
     apt-utils && \
     apt-get -qq install \
     software-properties-common \
-    python3 \
-    python3-dev && \
+    python3-dev \
+    python3-pip && \
     rm -rf /var/lib/apt/lists/*
 
-# Install pip dependecies; we have to use pip, since cython provided by apt-get is too old.
-RUN wget -q https://bootstrap.pypa.io/get-pip.py -O get-pip.py && \
-    python3 get-pip.py
-
 
+# Install FEniCS
 RUN add-apt-repository -y ppa:fenics-packages/fenics && \
     apt-get -qq update && \
     apt-get -qq install --no-install-recommends fenics && \
     rm -rf /var/lib/apt/lists/*
 
-
+# Upgrade pip to newest version (pip version from 18.04 apt-get is outdated)
+RUN pip3 install --user --upgrade pip
+# Use pip to install cython (apt-get version of cython is too old)
 RUN pip3 install --user cython # TODO: can we put this dependency into requirements.txt of python?
 
 USER precice

precice/Dockerfile.Ubuntu2004.home

@@ -15,8 +15,9 @@ RUN apt-get -qq update && apt-get -qq install \
     libeigen3-dev \
     libxml2-dev \
     git \
-    python-numpy \
-    python-dev \
+    python3-numpy \
+    python3-dev \
+    petsc-dev \
     wget \
     bzip2 \
     cmake && \