some fixes with yum packages

Author: GbArc

lib/travis/build/addons.rb

@@ -2,6 +2,7 @@
 require 'travis/build/addons/apt'
 require 'travis/build/addons/apt_packages'
 require 'travis/build/addons/apt_retries'
+require 'travis/build/addons/yum'
 require 'travis/build/addons/snaps'
 require 'travis/build/addons/artifacts'
 require 'travis/build/addons/chrome'

lib/travis/build/addons/yum.rb

@@ -41,7 +41,7 @@ def before_configure
             retries=5
             timeout=30
           YUM_CONF
-          sh.cmd %Q{su -m root -c "mv #{tmp_dest} ${TRAVIS_ROOT}/usr/local/etc/yum.conf"}
+          sh.cmd %Q{sudo mv #{tmp_dest} ${TRAVIS_ROOT}/usr/local/etc/yum.conf}
         end
 
         def config
@@ -52,7 +52,7 @@ def install_yum
           sh.echo "Installing #{config_yum.count} packages", ansi: :yellow
 
           packages = config_yum.map{|v| Shellwords.escape(v)}.join(' ')
-          sh.cmd "su -m root -c 'yum install -y #{packages}'", echo: true, timing: true, assert: true
+          sh.cmd "sudo yum install -y #{packages}", echo: true, timing: true, assert: true
         end
 
         def config_yum