title: Way to force docker to accept and proceed with building the image with a non zero response/code
body: <p>I have the following dockerfile which is very simple using Centos:latest as the base image.
  docker file exits on any command other than 0 as error code/code
  yum check-update returns a status code of 100 for successful operation</p>
  
  <p>The docker file is as follows</p>
  
  <pre><code>FROM centos:latest
  MAINTAINER xyz (xyz@gmail.com)
  ENTRYPOINT ["/bin/sh", "-lc", "ocp-indent"]
  RUN yum -y check-update
  </code></pre>
  
  <p>When I try to build the image , the process is getting run as follows, but it gets killed without building the image successfully</p>
  
  <pre><code>Sending build context to Docker daemon  2.048kB
  Step 1/4 : FROM centos:latest
  latest: Pulling from library/centos
  7dc0dca2b151: Pull complete 
  Digest:   
  sha256:b67d21dfe609ddacf404589e04631d90a342921e81c40aeaf3391f6717fa5322
  Status: Downloaded newer image for centos:latest
  ---&gt; 49f7960eb7e4
  Step 2/4 : MAINTAINER xyz (xyz@gmail.com)
  ---&gt; Running in c5284bbfb10e
  ---&gt; b2334a38cc19
  Removing intermediate container c5284bbfb10e
  Step 3/4 : ENTRYPOINT /bin/sh -lc ocp-indent
  ---&gt; Running in 55b9adafca35
  ---&gt; 02df626e85d6
  Removing intermediate container 55b9adafca35
  Step 4/4 : RUN yum check-update
  ---&gt; Running in 3f9d47e74522
  Loaded plugins: fastestmirror, ovl
  Determining fastest mirrors
  * base: mirror.its.dal.ca
  * extras: centos.les.net
  * updates: centos.les.net
  
  binutils.x86_64                    2.27-28.base.el7_5.1                  
  updates
  gnupg2.x86_64                      2.0.22-5.el7_5                        
  updates
  python.x86_64                      2.7.5-69.el7_5                        
  updates
  python-libs.x86_64                 2.7.5-69.el7_5                        
  updates
  **The command '/bin/sh -c yum check-update' returned a non-zero code: 100**
  </code></pre>