Add -R option to ci/build.py to avoid rebuilding containers (#15426)
Add -R option to ci/build.py to avoid rebuilding containers (#15426)

There are a couple of problems which trigger continuous rebuild of the containers which have difficult solutions, this option enables a workaround.
https://github.com/docker/docker.github.io/issues/8886
yajiedesign/mxnet,yajiedesign/mxnet,leezu/mxnet,ForkedReposBak/mxnet,leezu/mxnet,ForkedReposBak/mxnet,sxjscience/mxnet,larroy/mxnet,sxjscience/mxnet,yajiedesign/mxnet,larroy/mxnet,reminisce/mxnet,DickJC123/mxnet,reminisce/mxnet,reminisce/mxnet,eric-haibin-lin/mxnet,sxjscience/mxnet,larroy/mxnet,tlby/mxnet,sxjscience/mxnet,sxjscience/mxnet,tlby/mxnet,ForkedReposBak/mxnet,sxjscience/mxnet,zhreshold/mxnet,yajiedesign/mxnet,tlby/mxnet,zhreshold/mxnet,reminisce/mxnet,tlby/mxnet,DickJC123/mxnet,eric-haibin-lin/mxnet,eric-haibin-lin/mxnet,szha/mxnet,yajiedesign/mxnet,tlby/mxnet,szha/mxnet,reminisce/mxnet,larroy/mxnet,tlby/mxnet,apache/incubator-mxnet,larroy/mxnet,tlby/mxnet,apache/incubator-mxnet,ForkedReposBak/mxnet,eric-haibin-lin/mxnet,leezu/mxnet,larroy/mxnet,tlby/mxnet,leezu/mxnet,reminisce/mxnet,eric-haibin-lin/mxnet,leezu/mxnet,zhreshold/mxnet,reminisce/mxnet,DickJC123/mxnet,eric-haibin-lin/mxnet,ForkedReposBak/mxnet,szha/mxnet,zhreshold/mxnet,leezu/mxnet,sxjscience/mxnet,sxjscience/mxnet,reminisce/mxnet,ForkedReposBak/mxnet,zhreshold/mxnet,ForkedReposBak/mxnet,yajiedesign/mxnet,zhreshold/mxnet,leezu/mxnet,leezu/mxnet,tlby/mxnet,zhreshold/mxnet,eric-haibin-lin/mxnet,tlby/mxnet,apache/incubator-mxnet,yajiedesign/mxnet,reminisce/mxnet,zhreshold/mxnet,szha/mxnet,larroy/mxnet,ForkedReposBak/mxnet,leezu/mxnet,larroy/mxnet,reminisce/mxnet,larroy/mxnet,szha/mxnet,apache/incubator-mxnet,ForkedReposBak/mxnet,eric-haibin-lin/mxnet,zhreshold/mxnet,szha/mxnet,yajiedesign/mxnet,szha/mxnet,DickJC123/mxnet,yajiedesign/mxnet,eric-haibin-lin/mxnet,szha/mxnet,szha/mxnet,sxjscience/mxnet