layer nodejs images on top of s2i-core instead of s2i-base

As we are installing npm packages in s2i-base that only get
removed during the build of actual nodejs images layered on top,
let us instead build the images directly on top of s2i-core to
preserve some image size.

14/Dockerfile.rhel7

@@ -1,4 +1,4 @@
-FROM rhscl/s2i-base-rhel7:1
+FROM rhscl/s2i-core-rhel7:1
 
 # This image provides a Node.JS environment you can use to run your Node.JS
 # applications.
@@ -57,7 +57,6 @@ LABEL summary="$SUMMARY" \
 
 RUN yum install -y yum-utils && \
     prepare-yum-repositories rhel-server-rhscl-7-rpms && \
-    ( [ "rh-${NAME}${NODEJS_VERSION}" != "${NODEJS_SCL}" ] && yum remove -y ${NODEJS_SCL}\* || : ) && \
     INSTALL_PKGS="rh-nodejs${NODEJS_VERSION} rh-nodejs${NODEJS_VERSION}-npm rh-nodejs${NODEJS_VERSION}-nodejs-nodemon nss_wrapper" && \
     ln -s /usr/lib/node_modules/nodemon/bin/nodemon.js /usr/bin/nodemon && \
     yum install -y --setopt=tsflags=nodocs $INSTALL_PKGS && \

14/Dockerfile.rhel8

@@ -1,4 +1,4 @@
-FROM ubi8/s2i-base:1
+FROM ubi8/s2i-core:1
 
 # This image provides a Node.JS environment you can use to run your Node.JS
 # applications.
@@ -49,10 +49,9 @@ LABEL summary="$SUMMARY" \
       help="For more information visit https://github.com/sclorg/s2i-nodejs-container" \
       usage="s2i build <SOURCE-REPOSITORY> ubi8/$NAME-$NODEJS_VERSION:latest <APP-NAME>"
 
-RUN yum -y module reset nodejs && yum -y module enable nodejs:$NODEJS_VERSION && \
+RUN yum -y module enable nodejs:$NODEJS_VERSION && \
     INSTALL_PKGS="nodejs npm nodejs-nodemon nss_wrapper" && \
     ln -s /usr/lib/node_modules/nodemon/bin/nodemon.js /usr/bin/nodemon && \
-    yum remove -y $INSTALL_PKGS && \
     yum install -y --setopt=tsflags=nodocs $INSTALL_PKGS && \
     rpm -V $INSTALL_PKGS && \
     yum -y clean all --enablerepo='*'