Deprecate cpl (#203)

Author: rafaelgomesxyz

cpl.gemspec

@@ -38,4 +38,8 @@ Gem::Specification.new do |spec|
   spec.executables = ["cpl"]
 
   spec.metadata["rubygems_mfa_required"] = "true"
+
+  spec.post_install_message = "DEPRECATED: The `cpl` gem has been renamed to `cpflow` " \
+                              "and will no longer be supported. " \
+                              "Please switch to `shakaflow` as soon as possible."
 end

lib/cpl.rb

@@ -60,13 +60,24 @@ class Cli < Thor # rubocop:disable Metrics/ClassLength
     def self.start(*args)
       ENV["CPLN_SKIP_UPDATE_CHECK"] = "true"
 
+      warn_deprecated_gem
       check_cpln_version
       check_cpl_version
       fix_help_option
 
       super(*args)
     end
 
+    def self.warn_deprecated_gem
+      return if @warned_deprecated_gem
+
+      @warned_deprecated_gem = true
+
+      ::Shell.warn_deprecated("This gem has been renamed to `cpflow` " \
+                              "and will no longer be supported. " \
+                              "Please switch to `cpflow` as soon as possible.")
+    end
+
     def self.check_cpln_version # rubocop:disable Metrics/MethodLength
       return if @checked_cpln_version