Install Bundler 1.17.x by default, too

Author: jeremy

1.8.7-p374

@@ -25,6 +25,14 @@ index a15309d502..35a2f03052 100644
 EOF
 }
 
+install_gem() {
+  RBENV_VERSION="$VERSION_NAME" rbenv-exec gem install "$@"
+}
+
+install_bundler() {
+  install_gem bundler -v "< 2"
+}
+
 # Clang errors on warnings. Tell it to ignore this one.
 export RUBY_CFLAGS="-Wno-error=implicit-function-declaration"
 
@@ -35,3 +43,4 @@ package_option ruby configure --with-openssl-dir="$(brew --prefix basecamp/dev/o
 require_gcc
 install_package "ruby-1.8.7-p374" "https://cache.ruby-lang.org/pub/ruby/1.8/ruby-1.8.7-p374.tar.bz2#b4e34703137f7bfb8761c4ea474f7438d6ccf440b3d35f39cc5e4d4e239c07e3" freshen_automake_config patch_lex_c99 auto_tcltk standard
 install_package "rubygems-1.8.23" "https://rubygems.org/rubygems/rubygems-1.8.23.tgz#e4a1c6bbaac411eaab94deae78228b7584033a1f10a022f52bffa9613aa29061" ruby
+install_bundler