Log Message:
Update ruby-haml to 5.0.1

## 5.0.1

Released on May 3, 2017
([diff](https://github.com/haml/haml/compare/v5.0.0...v5.0.1)).

* Fix parsing attributes including string interpolation. \ 
[#917](https://github.com/haml/haml/pull/917) \ 
[#921](https://github.com/haml/haml/issues/921)
* Stop distributing test files in gem package and allow installing on Windows.
* Use ActionView's Erubi/Erubis handler for erb filter only on ActionView. \ 
[#914](https://github.com/haml/haml/pull/914)

## 5.0.0

Released on April 26, 2017
([diff](https://github.com/haml/haml/compare/4.0.7...v5.0.0)).

Breaking Changes

* Haml now requires Ruby 2.0.0 or above.
* Rails 3 is no longer supported, matching the official
  [Maintenance Policy for Ruby on \ 
Rails](http://weblog.rubyonrails.org/2013/2/24/maintenance-policy-for-ruby-on-rails/).
  (Tee Parham)
* The `haml` command's debug option (`-d`) no longer executes the Haml code, but
  rather checks the generated Ruby syntax for errors.
* Drop parser/compiler accessor from `Haml::Engine`. Modify \ 
`Haml::Engine#initialize` options
  or `Haml::Template.options` instead. (Takashi Kokubun)
* Drop dynamic quotes support and always escape `'` for \ 
`escape_html`/`escape_attrs` instead.
  Also, escaped results are slightly changed and always unified to the same \ 
characters. (Takashi Kokubun)
* Don't preserve newlines in attributes. (Takashi Kokubun)
* HTML escape interpolated code in filters.
  [#770](https://github.com/haml/haml/pull/770)
  (Matt Wildig)

        :javascript
          #{JSON.generate(foo: "bar")}
        Haml 4 output: {"foo":"bar"}
        Haml 5 output: {"foo":"bar"}

Added

* Add a tracing option. When enabled, Haml will output a data-trace attribute on \ 
each tag showing the path
  to the source Haml file from which it was generated. Thanks [Alex \ 
Babkin](https://github.com/ababkin).
* Add `haml_tag_if` to render a block, conditionally wrapped in another element \ 
(Matt Wildig)
* Support Rails 5.1 Erubi template handler.
* Support Sprockets 3. Thanks [Sam Davies](https://github.com/samphilipd) and \ 
[Jeremy Venezia](https://github.com/jvenezia).
* General performance and memory usage improvements. (Akira Matsuda)
* Analyze attribute values by Ripper and render static attributes beforehand. \ 
(Takashi Kokubun)
* Optimize attribute rendering about 3x faster. (Takashi Kokubun)
* Add temple gem as dependency and create `Haml::TempleEngine` class.
  Some methods in `Haml::Compiler` are migrated to `Haml::TempleEngine`. \ 
(Takashi Kokubun)

Fixed

* Fix for attribute merging. When an attribute method (or literal nested hash)
  was used in an old style attribute hash and there is also a (non-static) new
  style hash there is an error. The fix can result in different behavior in
  some circumstances. See the [commit \ 
message](https://github.com/haml/haml/tree/e475b015d3171fb4c4f140db304f7970c787d6e3)
  for detailed info. (Matt Wildig)
* Make escape_once respect hexadecimal references. (Matt Wildig)
* Don't treat the 'data' attribute specially when merging attribute hashes. \ 
(Matt Wildig and Norman Clarke)
* Fix #@foo and #$foo style interpolation that was not working in html_safe \ 
mode. (Akira Matsuda)
* Allow `@` as tag's class name. Thanks [Joe Bartlett](https://github.com/redoPop).
* Raise `Haml::InvalidAttributeNameError` when attribute name includes invalid \ 
characters. (Takashi Kokubun)
* Don't ignore unexpected exceptions on initializing `ActionView::OutputBuffer`. \ 
(Takashi Kokubun)