codecov-ruby breaks gems has a dependency for colorize

[unhappychoice]

Ref: circleci-tools/circleci-cli#217

First of all, thank you for this awesome product 🙏
I'm using codecov for almost all of my repositories.

Description

1. My gem depended on both of colorize and codecov-ruby.
2. codecov-ruby 0.2.8 ( Remove colorize depedency #94 ) overwrites colorize methods.
3. My gem is broken.

Suggestion

I think gems used as a library should not monkey-patch the Ruby classes,
except in case of getting permission from users or getting things known to them at least.

So, I think we should use simple methods instead of monkey-patching String
( or use Refinement? But I don't think it's not worth using such a function for the colorize methods.