Add ability to specify a custom value in matcher

[rmm5t]

What does it do?

• Clean cops in strip_attributes/matchers
• Add bin/console
• Add rake binstub
• Add ability to customize the value used in the matcher

What else do you need to know?

This helps in scenarios where an attribute is normalized (e.g. upcased or downcased).

Usage

must strip_attribute(:ticker).using("AAPL")