refactor: make BANNER constant private and simplify validation checks for quiet and verbose options

Author: jcouball

exe/revert-github-release

@@ -76,7 +76,7 @@ class Parser
     COMMAND
   end
 
-  BANNER = <<~BANNER.freeze
+  private_constant BANNER = <<~BANNER.freeze
     Usage:
     #{File.basename($PROGRAM_NAME)} [--help | --version]
 

lib/create_github_release/command_line/validations.rb

@@ -119,7 +119,7 @@ class ValidateQuiet < Base
         # @return [Boolean]
         # @api private
         def valid?
-          options.quiet == true || options.quiet == false
+          [true, false].include? options.quiet
         end
 
         # Called when valid? is `false` to return the error messages
@@ -137,7 +137,7 @@ class ValidateVerbose < Base
         # @return [Boolean]
         # @api private
         def valid?
-          options.verbose == true || options.verbose == false
+          [true, false].include? options.verbose
         end
 
         # Called when valid? is `false` to return the error messages