dep: upgrade mini_portile 2.7 to 2.8

to handle .tar.xz files

Author: flavorjones

ext/nokogiri/extconf.rb

@@ -15,7 +15,7 @@
 REQUIRED_LIBXML_VERSION = "2.6.21"
 RECOMMENDED_LIBXML_VERSION = "2.9.3"
 
-REQUIRED_MINI_PORTILE_VERSION = "~> 2.7.0" # keep this version in sync with the one in the gemspec
+REQUIRED_MINI_PORTILE_VERSION = "~> 2.8.0" # keep this version in sync with the one in the gemspec
 REQUIRED_PKG_CONFIG_VERSION = "~> 1.1"
 
 # Keep track of what versions of what libraries we build against

nokogiri.gemspec

@@ -318,7 +318,7 @@ Gem::Specification.new do |spec|
   spec.extra_rdoc_files += Dir.glob("README.md")
   spec.rdoc_options = ["--main", "README.md"]
 
-  spec.add_runtime_dependency("mini_portile2", "~> 2.7.0") unless java_p # keep version in sync with extconf.rb
+  spec.add_runtime_dependency("mini_portile2", "~> 2.8.0") unless java_p # keep version in sync with extconf.rb
   spec.add_runtime_dependency("racc", "~> 1.4")
 
   spec.add_development_dependency("bundler", "~> 2.2")