Add deprecation warning for gazebo to gz-sim instead

Signed-off-by: methylDragon <methylDragon@gmail.com>

src/gz.in

@@ -151,7 +151,7 @@ end
 # Check that we have at least one configuration file with gz commands.
 unless yaml_found
   puts "I cannot find any available 'gz' command:\n"\
-       "\t* Did you install any gazebo library?\n"\
+       "\t* Did you install any Gazebo library?\n"\
        "\t* Did you set the GZ_CONFIG_PATH environment variable?\n"\
        "\t    E.g.: export GZ_CONFIG_PATH=$HOME/local/share/gz\n"
   exit(-1)
@@ -300,12 +300,6 @@ cmd_rb_library = commands[ARGV[0]].at(version_index)[1]['library_path']
 require cmd_rb_library
 cmd = Cmd.new
 
-# TODO(CH3): Deprecated. Remove on tock.
-# Print deprecation warning
-if ARGV[0] == 'gazebo'
-  puts 'The `gazebo` verb is deprecated. Please use `sim` instead.'
-end
-
 # Set the process title to something nice.
 Process.setproctitle("gz #{ARGV.join(' ')}")