開発版のGemをBundlerからインストールする


Jekyll 2.0.3がマルチバイトに対応していない部分があってサイトがビルドできない。。。

```
$ bundle exec jekyll build --trace
Configuration file: _config.yml
       Deprecation: The 'pygments' configuration option has been renamed to 'highlighter'. Please update your config file accordingly. The allowed values are 'rouge', 'pygments' or null.
            Source: ./
       Destination: _site
      Generating... 
.rvm/gems/ruby-2.0.0-p451-rvm/gems/jekyll-2.0.3/lib/jekyll.rb:121:in `gsub!': invalid byte sequence in US-ASCII (ArgumentError)
	from .rvm/gems/ruby-2.0.0-p451-rvm/gems/jekyll-2.0.3/lib/jekyll.rb:121:in `sanitized_path'
	from .rvm/gems/ruby-2.0.0-p451-rvm/gems/jekyll-2.0.3/lib/jekyll/post.rb:276:in `destination'
	from .rvm/gems/ruby-2.0.0-p451-rvm/gems/jekyll-2.0.3/lib/jekyll/cleaner.rb:43:in `block in new_files'
	from .rvm/gems/ruby-2.0.0-p451-rvm/gems/jekyll-2.0.3/lib/jekyll/site.rb:420:in `block (2 levels) in each_site_file'
	from .rvm/gems/ruby-2.0.0-p451-rvm/gems/jekyll-2.0.3/lib/jekyll/site.rb:419:in `each'
	from .rvm/gems/ruby-2.0.0-p451-rvm/gems/jekyll-2.0.3/lib/jekyll/site.rb:419:in `block in each_site_file'
	from .rvm/gems/ruby-2.0.0-p451-rvm/gems/jekyll-2.0.3/lib/jekyll/site.rb:418:in `each'
	from .rvm/gems/ruby-2.0.0-p451-rvm/gems/jekyll-2.0.3/lib/jekyll/site.rb:418:in `each_site_file'
	from .rvm/gems/ruby-2.0.0-p451-rvm/gems/jekyll-2.0.3/lib/jekyll/cleaner.rb:43:in `new_files'
	from .rvm/gems/ruby-2.0.0-p451-rvm/gems/jekyll-2.0.3/lib/jekyll/cleaner.rb:24:in `obsolete_files'
	from .rvm/gems/ruby-2.0.0-p451-rvm/gems/jekyll-2.0.3/lib/jekyll/cleaner.rb:15:in `cleanup!'
	from .rvm/gems/ruby-2.0.0-p451-rvm/gems/jekyll-2.0.3/lib/jekyll/site.rb:255:in `cleanup'
	from .rvm/gems/ruby-2.0.0-p451-rvm/gems/jekyll-2.0.3/lib/jekyll/site.rb:44:in `process'
	from .rvm/gems/ruby-2.0.0-p451-rvm/gems/jekyll-2.0.3/lib/jekyll/command.rb:43:in `process_site'
	from .rvm/gems/ruby-2.0.0-p451-rvm/gems/jekyll-2.0.3/lib/jekyll/commands/build.rb:46:in `build'
	from .rvm/gems/ruby-2.0.0-p451-rvm/gems/jekyll-2.0.3/lib/jekyll/commands/build.rb:30:in `process'
	from .rvm/gems/ruby-2.0.0-p451-rvm/gems/jekyll-2.0.3/lib/jekyll/commands/build.rb:17:in `block (2 levels) in init_with_program'
	from .rvm/gems/ruby-2.0.0-p451-rvm/gems/mercenary-0.3.3/lib/mercenary/command.rb:220:in `call'
	from .rvm/gems/ruby-2.0.0-p451-rvm/gems/mercenary-0.3.3/lib/mercenary/command.rb:220:in `block in execute'
	from .rvm/gems/ruby-2.0.0-p451-rvm/gems/mercenary-0.3.3/lib/mercenary/command.rb:220:in `each'
	from .rvm/gems/ruby-2.0.0-p451-rvm/gems/mercenary-0.3.3/lib/mercenary/command.rb:220:in `execute'
	from .rvm/gems/ruby-2.0.0-p451-rvm/gems/mercenary-0.3.3/lib/mercenary/program.rb:35:in `go'
	from .rvm/gems/ruby-2.0.0-p451-rvm/gems/mercenary-0.3.3/lib/mercenary.rb:22:in `program'
	from .rvm/gems/ruby-2.0.0-p451-rvm/gems/jekyll-2.0.3/bin/jekyll:18:in `<top (required)>'
	from .rvm/gems/ruby-2.0.0-p451-rvm/bin/jekyll:23:in `load'
	from .rvm/gems/ruby-2.0.0-p451-rvm/bin/jekyll:23:in `<main>'
	from .rvm/gems/ruby-2.0.0-p451-rvm/bin/ruby_executable_hooks:15:in `eval'
	from .rvm/gems/ruby-2.0.0-p451-rvm/bin/ruby_executable_hooks:15:in `<main>'
```

この問題はJekyllでも報告されていてMasterでは修正済だけど、修正はまだリリースされていない。

- [jekyll 2.0.3 | Error: invalid byte sequence in US-ASCII · Issue #2379 · jekyll/jekyll](https://github.com/jekyll/jekyll/issues/2379)

GemfileのJekyllの指定を次のように変更

```
source 'https://rubygems.org'

gem 'jekyll' , git: 'https://github.com/jekyll/jekyll.git', branch: 'master'
gem 'redcarpet'
gem 'rake'
gem 'sass'
gem 'rb-fsevent'
gem 'json'
gem 'jekyll-assets'

group :development do
  gem 'cal_exporter'
end

```

bundle updateしてbuild成功。
バージョンのところにdevとか書いて開発版入れられたりするのかな。