do not install ronn when setting up the chroot environments

It is not yet used for anything, and installing it fails due to a
dependency on mustache 0.99.7 which requires Ruby 1.9.3, which is
not available in all the environments.

scripts/build.py

@@ -241,7 +241,7 @@ deb http://security.debian.org/   wheezy/updates main contrib non-free"""),
         ('shell', 'apt-get dist-upgrade --assume-yes'),
         ('shell', 'apt-get install --assume-yes xz-utils libssl-dev libpng-dev libjpeg8-dev zlib1g-dev rubygems'),
         ('shell', 'apt-get install --assume-yes libfontconfig1-dev libfreetype6-dev libx11-dev libxext-dev libxrender-dev'),
-        ('shell', 'gem install fpm ronn --no-ri --no-rdoc'),
+        ('shell', 'gem install fpm --no-ri --no-rdoc'),
         ('write_file', 'update.sh', 'apt-get update\napt-get dist-upgrade --assume-yes\n'),
         ('fpm_setup',  'fpm_package.sh'),
         ('schroot_conf', 'Debian Wheezy')
@@ -257,7 +257,7 @@ deb http://archive.ubuntu.com/ubuntu/ trusty-security main restricted universe m
         ('shell', 'apt-get dist-upgrade --assume-yes'),
         ('shell', 'apt-get install --assume-yes xz-utils libssl-dev libpng-dev libjpeg-turbo8-dev zlib1g-dev ruby-dev'),
         ('shell', 'apt-get install --assume-yes libfontconfig1-dev libfreetype6-dev libx11-dev libxext-dev libxrender-dev'),
-        ('shell', 'gem install fpm ronn --no-ri --no-rdoc'),
+        ('shell', 'gem install fpm --no-ri --no-rdoc'),
         ('write_file', 'update.sh', 'apt-get update\napt-get dist-upgrade --assume-yes\n'),
         ('fpm_setup',  'fpm_package.sh'),
         ('schroot_conf', 'Ubuntu Trusty')
@@ -273,7 +273,7 @@ deb http://archive.ubuntu.com/ubuntu/ precise-security main restricted universe
         ('shell', 'apt-get dist-upgrade --assume-yes'),
         ('shell', 'apt-get install --assume-yes xz-utils libssl-dev libpng-dev libjpeg8-dev zlib1g-dev rubygems'),
         ('shell', 'apt-get install --assume-yes libfontconfig1-dev libfreetype6-dev libx11-dev libxext-dev libxrender-dev'),
-        ('shell', 'gem install fpm ronn --no-ri --no-rdoc'),
+        ('shell', 'gem install fpm --no-ri --no-rdoc'),
         ('write_file', 'update.sh', 'apt-get update\napt-get dist-upgrade --assume-yes\n'),
         ('fpm_setup',  'fpm_package.sh'),
         ('schroot_conf', 'Ubuntu Precise')
@@ -288,7 +288,7 @@ deb http://archive.ubuntu.com/ubuntu/ precise-security main restricted universe
         ('append_file:amd64', 'etc/yum.conf', 'exclude = *.i?86\n'),
         ('shell', 'yum install -y gcc gcc-c++ make diffutils perl ruby-devel rubygems rpm-build libffi-devel'),
         ('shell', 'yum install -y openssl-devel libX11-devel libXrender-devel libXext-devel fontconfig-devel freetype-devel libjpeg-devel libpng-devel zlib-devel'),
-        ('shell', 'gem install fpm ronn --no-ri --no-rdoc'),
+        ('shell', 'gem install fpm --no-ri --no-rdoc'),
         ('write_file', 'update.sh', 'yum update -y\n'),
         ('fpm_setup',  'fpm_package.sh'),
         ('schroot_conf', 'CentOS 5')
@@ -300,7 +300,7 @@ deb http://archive.ubuntu.com/ubuntu/ precise-security main restricted universe
         ('append_file:amd64', 'etc/yum.conf', 'exclude = *.i?86\n'),
         ('shell', 'yum install -y gcc gcc-c++ make diffutils perl ruby-devel rubygems rpm-build libffi-devel'),
         ('shell', 'yum install -y openssl-devel libX11-devel libXrender-devel libXext-devel fontconfig-devel freetype-devel libjpeg-devel libpng-devel zlib-devel'),
-        ('shell', 'gem install fpm ronn --no-ri --no-rdoc'),
+        ('shell', 'gem install fpm --no-ri --no-rdoc'),
         ('write_file', 'update.sh', 'yum update -y\n'),
         ('fpm_setup',  'fpm_package.sh'),
         ('schroot_conf', 'CentOS 6')