Drop CHANGELOG.md — releases page is the source of truth

Gemspec changelog_uri now points to /releases instead of a tracked file.

Author: Fivell

CHANGELOG.md

@@ -18,9 +18,9 @@ Gem::Specification.new do |spec|
 
   spec.metadata["homepage_uri"]    = spec.homepage
   spec.metadata["source_code_uri"] = spec.homepage
-  spec.metadata["changelog_uri"]   = "#{spec.homepage}/blob/master/CHANGELOG.md"
+  spec.metadata["changelog_uri"]   = "#{spec.homepage}/releases"
 
-  spec.files = Dir["lib/**/*", "README.md", "CHANGELOG.md", "LICENSE.txt"]
+  spec.files = Dir["lib/**/*", "README.md", "LICENSE.txt"]
   spec.require_paths = ["lib"]
 
   spec.add_dependency "activeadmin", ">= 3.5", "< 5.0"