Adding support for optional Password Policy (#3032)

* adds resetTokenValidityDuration setting

* adds a validator to validate password that can be used to enforce strong
passwords

* adds unit tests for passwordPolicy.validator

* adds unit tests to to fail reset password function if password is not in a valid format

* updates README.md for passwordPolicy

* prevents duplicate check for password validator in updateUserPassword

* adds optional setting to disallow username in password

* updates test cases to use fdescribe instead of describe

* updates test cases to use request-promise instead of request

* adds ability to use a RegExp or Callback function or both for a passwordPolicy.validator

* expect username parameter in redirect to password_reset_success

* adds support for _perishable_token_expires_at in postgres

src/cli/definitions/parse-server.js

@@ -136,6 +136,11 @@ export default {
     help: "account lockout policy for failed login attempts",
     action: objectParser
   },
+  "passwordPolicy": {
+    env: "PARSE_SERVER_PASSWORD_POLICY",
+    help: "Password policy for enforcing password related rules",
+    action: objectParser
+  },
   "appName": {
     env: "PARSE_SERVER_APP_NAME",
     help: "Sets the app name"