Update README.md
Merge pull request #25 from Gerasim-Stan/patch-1

Fix typo at String#to_proc
Improve consistency of README

Better match description with code samples
Merge pull request #27 from agalloch/patch-1

Improve consistency of README
Added rubocop files
Merge pull request #28 from svetliomihailov/add_rubocop_files

Added rubocop files
Introduce Object#define_singleton_method task
Merge branch 'master' of https://github.com/HackBulgaria/Core-Ruby-1