Log Message:
Update ruby-liquid to 4.0.0 required by puppet 4.10.4.

## 4.0.0

### Changed
* Render an opaque internal error by default for non-Liquid::Error (#835) [Dylan \ 
Thacker-Smith]
* Ruby 2.0 support dropped (#832) [Dylan Thacker-Smith]
* Add to_number Drop method to allow custom drops to work with number filters (#731)
* Add strict_variables and strict_filters options to detect undefined references \ 
(#691)
* Improve loop performance (#681) [Florian Weingarten]
* Rename Drop method `before_method` to `liquid_method_missing` (#661) [Thierry \ 
Joyal]
* Add url_decode filter to invert url_encode (#645) [Larry Archer]
* Add global_filter to apply a filter to all output (#610) [Loren Hale]
* Add compact filter (#600) [Carson Reinke]
* Rename deprecated "has_key?" and "has_interrupt?" methods \ 
(#593) [Florian Weingarten]
* Include template name with line numbers in render errors (574) [Dylan \ 
Thacker-Smith]
* Add sort_natural filter (#554) [Martin Hanzel]
* Add forloop.parentloop as a reference to the parent loop (#520) [Justin Li]
* Block parsing moved to BlockBody class (#458) [Dylan Thacker-Smith]
* Add concat filter to concatenate arrays (#429) [Diogo Beato]
* Ruby 1.9 support dropped (#491) [Justin Li]
* Liquid::Template.file_system's read_template_file method is no longer passed \ 
the context. (#441) [James Reid-Smith]
* Remove support for `liquid_methods`
* Liquid::Template.register_filter raises when the module overrides registered \ 
public methods as private or protected (#705) [Gaurav Chande]

### Fixed
* Fix map filter when value is a Proc (#672) [Guillaume Malette]
* Fix truncate filter when value is not a string (#672) [Guillaume Malette]
* Fix behaviour of escape filter when input is nil (#665) [Tanel Jakobsoo]
* Fix sort filter behaviour with empty array input (#652) [Marcel Cary]
* Fix test failure under certain timezones (#631) [Dylan Thacker-Smith]
* Fix bug in uniq filter (#595) [Florian Weingarten]
* Fix bug when "blank" and "empty" are used as variable \ 
names (#592) [Florian Weingarten]
* Fix condition parse order in strict mode (#569) [Justin Li]
* Fix naming of the "context variable" when dynamically including a \ 
template (#559) [Justin Li]
* Gracefully accept empty strings in the date filter (#555) [Loren Hale]
* Fix capturing into variables with a hyphen in the name (#505) [Florian Weingarten]
* Fix case sensitivity regression in date standard filter (#499) [Kelley Reynolds]
* Disallow filters with no variable in strict mode (#475) [Justin Li]
* Disallow variable names in the strict parser that are not valid in the lax \ 
parser (#463) [Justin Li]
* Fix BlockBody#warnings taking exponential time to compute (#486) [Justin Li]