Rename from Picop to Picopackage

exe/ppkg

@@ -4,10 +4,10 @@
 lib_path = File.expand_path('../lib', __dir__)
 $LOAD_PATH.unshift(lib_path) unless $LOAD_PATH.include?(lib_path)
 
-require 'picop'
+require 'picopackage'
 
 begin
-  Picop::CLI.run(ARGV)
+  Picopackage::CLI.run(ARGV)
 rescue => e
   warn "Error: #{e.message}"
   warn e.backtrace if ENV['DEBUG']