Fix bcrypt warnings

`gen_salt` and `encrypt` are now deprecated in favor of `genSalt` and `hash`.
I also changed the code to just call bcrypt.hash with the desired salt length
instead of generating the salt separately. Less code that does the same job. :)
upgraded dependencies to recent versions
Merge pull request #83 from sespindola/upgrade_dependencies_versions

upgraded dependencies to recent versions
Merge pull request #65 from andrew12/fix_bcrypt_warnings

Fix bcrypt warnings