Set minimum Ruby version appropriately. (#15)

Author: ioquatix

.github/workflows/test.yaml

@@ -21,7 +21,7 @@ jobs:
           - macos
 
         ruby:
-          - "2.7"
+          - "2.7.6"
           - "3.0"
           - "3.1"
           - "3.2"

protocol-websocket.gemspec

@@ -17,7 +17,7 @@ Gem::Specification.new do |spec|
 
 	spec.files = Dir.glob(['{lib}/**/*', '*.md'], File::FNM_DOTMATCH, base: __dir__)
 
-	spec.required_ruby_version = ">= 2.5.0"
+	spec.required_ruby_version = ">= 2.7.6"
 
 	spec.add_dependency "protocol-http", "~> 0.2"
 	spec.add_dependency "protocol-http1", "~> 0.2"