fix centos8 build

Author: jspaleta

Dockerfile.centos8

@@ -6,6 +6,7 @@ ARG GREP_EXCLUDE='(ld.so|ld-linux-x86-64.so|libBrokenLocale.so|libSegFault.so|li
 
 
 RUN yum update -y && yum groupinstall -y "Development Tools" && yum install -y curl
+RUN yum install dnf-plugins-core && yum config-manager --set-enabled PowerTools
 
 RUN curl -L https://github.com/postmodern/ruby-install/archive/v0.7.0.tar.gz -o ruby-install-0.7.0.tar.gz && \
   tar -xzvf ruby-install-0.7.0.tar.gz && \

build_platforms.sh

@@ -44,7 +44,7 @@ if [[ retval -ne 0 ]]; then
 fi
 
 # CentOS 8 platform
-platform="centos8" test_platforms="centos:8 centos:7 debian:8 debian:9 debian:10 ubuntu:14.04 ubuntu:16.04 ubuntu:18.04" ./build_and_test_platform.sh
+platform="centos8" test_platforms="centos:8 debian:10 ubuntu:20.04" ./build_and_test_platform.sh
 retval=$?
 if [[ retval -ne 0 ]]; then
   exit $retval