Fix breakage in output with colors disabled

[andrehjr]

Investigating Pry::Helpers#strip_color I've found out that\e[1A\e[0G and the prompt was being removed from the text.

When the string was big enough, it wouldn't cause any trouble, as the output would just 'overwrite' it. But for strings such as 'puts "Hello"', or "'hello'.upcase" it would break the output in unexpected ways.

On master:

"\e[1A\e[0G[2] pry(main)> puts \e[31m\e[1;31m'\e[0m\e[31mhello\e[1;31m'\e[0m\e[31m\e[0m\e[1B\e[0G"

would become:

'hello'\e[1B\e[0G

With this fix:

"\e[1A\e[0G[2] pry(main)> puts 'hello'\e[1B\e[0G"

After my fix a spec on spec/pry_repl_spec.rb:127 started failing with RegexpError: premature end of char-class. A simple "string".match("do\n break #note the tab here\nend\n\e[1B\e[0G=> nil") raises an error. I've fixed that escaping the [ on 31590ea

It wasn't failing before because those strings were being matched by RSpec's fuzzy matcher and not by the regex itself.

Fixes #2148

[xjunior]

👍

[kyrylo]

Thanks!