Dockerfile.xenial-gcc9: Update cmake

Dockerfile.xenial-gcc9

@@ -24,7 +24,6 @@ ENV PACKAGES \
     gnupg2 \
     gawk \
     make \
-    cmake \
     nsis \
     python \
     python2.7 \
@@ -141,6 +140,17 @@ RUN set -eux; \
     echo "1" | update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-9 60 --slave /usr/bin/g++ g++ /usr/bin/g++-9; \
     echo "1" | update-alternatives --config gcc
 
+RUN set -eux; \
+    apt-get update -y; \
+    apt-get -y install apt-transport-https ca-certificates; \
+    wget -O - https://apt.kitware.com/keys/kitware-archive-latest.asc 2>/dev/null | gpg --dearmor - | sudo tee /etc/apt/trusted.gpg.d/kitware.gpg >/dev/null; \
+    apt-add-repository -y 'deb https://apt.kitware.com/ubuntu/ xenial main'; \
+    apt-get update -y; \
+    apt-get -y install kitware-archive-keyring; \
+    rm /etc/apt/trusted.gpg.d/kitware.gpg; \
+    apt-get -y install cmake; \
+    rm -rf /var/lib/apt/lists/*
+
 RUN echo "developer:developer" | chpasswd && adduser developer sudo
 
 ENV HOME=/developer