ci: use fedora 25 instead of fedora23

Fedora 23 is no longer supported. Current release is Fedora 25

Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com>
diff --git a/ci/build.sh b/ci/build.sh
index 64b862d..0ace0e1 100755
--- a/ci/build.sh
+++ b/ci/build.sh
@@ -1,6 +1,8 @@
 #!/bin/bash
 
-while getopts ":ahp:" opt; do
+CONTAINERS="ubuntu1404 fedora25"
+
+while getopts ":ahp:c:" opt; do
   case $opt in
     a)
       echo "Build firmware images for all the platforms"
@@ -10,11 +12,16 @@
       echo "Build firmware images for the platforms: $OPTARG"
       PLATFORMS=$OPTARG
       ;;
+    c)
+      echo "Build in container: $OPTARG"
+      CONTAINERS=$OPTARG
+      ;;
     h)
       echo "Usage: ./ci/build.sh [options] [--]"
       echo "-h          Print this help and exit successfully."
       echo "-a          Build firmware images for all the platform defconfig's."
       echo "-p          List of comma separated platform names to build images for particular platforms."
+      echo "-c          Container to run in"
       echo "Example:DOCKER_PREFIX=sudo ./ci/build.sh -a"
       echo -e "\tDOCKER_PREFIX=sudo ./ci/build.sh -p firestone"
       echo -e "\tDOCKER_PREFIX=sudo ./ci/build.sh -p garrison,palmetto,openpower_p9_mambo"
@@ -48,7 +55,7 @@
 	exit 1;
 fi
 
-for distro in ubuntu1404 fedora23;
+for distro in $CONTAINERS;
 do
 	base_dockerfile=ci/Dockerfile/$distro.`arch`
 	if [ ! -f $base_dockerfile ]; then
@@ -59,7 +66,7 @@
 		http_proxy=$HTTP_PROXY
 	fi
 	if [[ -n "$http_proxy" ]]; then
-	  if [[ "$distro" == fedora23 ]]; then
+	  if [[ "$distro" == fedora25 ]]; then
 	    PROXY="RUN echo \"proxy=${http_proxy}\" >> /etc/dnf/dnf.conf"
 	  fi
 	  if [[ "$distro" == ubuntu1404 ]]; then