message: Ensure that a new enough version of CMake is available in the Docker containers used by CI.
diff: @@ -14,3 +14,10 @@ RUN mkdir -p /tmp/android-ndk && \
  rm -rf /tmp/android-ndk
  ENV ANDROID_NDK_PATH /opt/android-ndk
  +
  +# Ensure a new enough version of CMake is available.
  +RUN cd /opt \
  + && wget https://cmake.org/files/v3.7/cmake-3.7.2-Linux-x86_64.tar.gz \
  + && tar zxvf cmake-3.7.2-Linux-x86_64.tar.gz
  +
  +ENV PATH "/opt/cmake-3.7.2-Linux-x86_64/bin:$PATH"
  