Bump gemojione gem to 2.5.0

gitlab_emoji.gemspec

@@ -13,5 +13,5 @@ Gem::Specification.new do |spec|
   spec.files         = `git ls-files`.split($/)
   spec.require_paths = ["lib"]
-  spec.add_dependency "gemojione", "~> 2.2", ">= 2.2.1"
+  spec.add_dependency "gemojione", "~> 2.5", ">= 2.5.0"
 end