update documentation
update README.md
update documentation
Merge pull request #18 from rollerworks/fix-docs

merge #18 update documentation (sstok)

This PR was merged into rollerworks:master branch.

Discussion
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Commits
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37b9dc009ff3e250b8e086d893c77ae74af95407 update documentation (sstok)
edc4b6d18aa4ff5fa0026bddabca5253feac3aa2 update README.md (sstok)
2f1d6bd3c801932b7409030a9f688c8c2fdb610f update documentation (sstok)
update PasswordRequirementsValidatorTest

Test that empty value is valid
fix PasswordStrengthTest failures
change PasswordStrengthValidator calculation

Only increase the strength when length is "higher",
not equal or higher. Using equal would make it always at least 1
adapt PSR-4 for tests
fix tests