add jekyll-seo-tag dependency

Author: DirtyF

minima.gemspec

@@ -19,6 +19,8 @@ Gem::Specification.new do |spec|
   spec.bindir        = "exe"
   spec.executables   = spec.files.grep(%r{^exe/}) { |f| File.basename(f) }
 
-  spec.add_runtime_dependency "jekyll", "~> 3.3"
+  spec.add_runtime_dependency "jekyll", "~> 3.5"
+  spec.add_runtime_dependency "jekyll-seo-tag", "~> 2.1"
+
   spec.add_development_dependency "bundler", "~> 1.12"
 end