Prevent long password denial of service

[cianmce]

As described here #27, this gem is vulnerable to DOS attacks

This PR:

1. Adds a limit for both usernames and passwords. A password length of 1,000 is recommended by OWASP

A limit of 1000 characters is sufficient to let the user choose a very big password without impacting the system.
https://www.owasp.org/index.php/Password_Storage_Cheat_Sheet#Input_password_size

2. Adds JS/Ruby tests that the password/username is being truncated
3. Removes unused $BREAKPOINT variable from ruby tests
4. Removes unneeded JS comment // assert @strength.invalid?

[cianmce]

@fnando does this seem like a reasonable solution to this security vulnerability?

[cianmce]

@fnando any reason for deleting the version file? This is causing CI to fail. Would you rather I increment it differently?

[cianmce]

@fnando can this be merged and released?

[cianmcelhinney]

@fnando bump
Can this be merged and released?