tell curl to follow redirects

dockerbuild/Dockerfile.debian-stretch

@@ -7,7 +7,7 @@ RUN apt-get update && apt-get -y install build-essential curl ca-certificates de
 RUN curl -s -k $go_pkg_url -o go.tar.gz && \
     tar -C /usr/local -xzf go.tar.gz && \
     rm go.tar.gz
-RUN curl -s https://github.com/Kitware/CMake/releases/download/v3.17.3/cmake-3.17.3-Linux-x86_64.sh -o cmake.sh && \
+RUN curl -s -L https://github.com/Kitware/CMake/releases/download/v3.17.3/cmake-3.17.3-Linux-x86_64.sh -o cmake.sh && \
     chmod +x cmake.sh && \
     ./cmake.sh && \
     rm cmake.sh

dockerbuild/Dockerfile.ubuntu-xenial

@@ -7,7 +7,7 @@ RUN apt-get update && apt-get -y install build-essential curl ca-certificates de
 RUN curl -s -k $go_pkg_url -o go.tar.gz && \
     tar -C /usr/local -xzf go.tar.gz && \
     rm go.tar.gz
-RUN curl -s https://github.com/Kitware/CMake/releases/download/v3.17.3/cmake-3.17.3-Linux-x86_64.sh -o cmake.sh && \
+RUN curl -s -L https://github.com/Kitware/CMake/releases/download/v3.17.3/cmake-3.17.3-Linux-x86_64.sh -o cmake.sh && \
     chmod +x cmake.sh && \
     ./cmake.sh && \
     rm cmake.sh