Fix Docker build script with multiple arguments

Also change the install order in the Centos dockerfile since some of
that needs to install after the enable command.

Author: code-asher

scripts/centos.dockerfile

@@ -1,7 +1,10 @@
 FROM centos:7
 
-RUN yum install -y centos-release-scl devtoolset-6 gcc-c++ git
+RUN yum install -y centos-release-scl
 RUN yum-config-manager --enable rhel-server-rhscl-7-rpms
+RUN yum install -y devtoolset-6
+RUN yum install -y gcc-c++
+RUN yum install -y git
 RUN rpm -Uvh http://dl.fedoraproject.org/pub/epel/7/x86_64/Packages/c/ccache-3.3.4-1.el7.x86_64.rpm
 
 RUN mkdir /root/node

scripts/docker.bash

@@ -33,9 +33,10 @@ function main() {
 
   # If there are command line arguments, use those. Otherwise loop through all
   # the existing dockerfiles.
-  if [[ -n "${1:-}" ]] ; then
-    local name="$1" ; shift
-    build "$name"
+  if [[ -n ${1:-} ]] ; then
+    while [[ -n ${1:-} ]] ; do
+      build "$1" ; shift
+    done
   else
     for dockerfile in *.dockerfile ; do
       local name="${dockerfile%.dockerfile}"