Support of BCrypt version 2b

[antonakospanos]

@tjschuck we are using the bcrypt gem and we need to upgrade to 2b hashes.

I found out that the effort is already done and merged into master in the context of PR-182 and PR-132.

The latest version, at the moment, though, is still version-3.1.12 since May 2018. Could we please tag the latest master so that we can use 2b hashes?

[tjschuck]

@antonakospanos You're right that it hasn't been put into a formal release yet. In the meantime, you can point your Gemfile at the master branch and it should work:

gem 'bcrypt', git: 'https://github.com/codahale/bcrypt-ruby.git'

If you don't want to bundle an unbounded master, you can peg it to a SHA as well:

gem 'bcrypt', git: 'https://github.com/codahale/bcrypt-ruby.git', ref: "84c8d7b"

A formal release is on my list, but I can't promise a date.