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

README.md

@@ -216,6 +216,7 @@ The client keys used with Parse are no longer necessary with Parse Server. If yo
 * `sessionLength` - The length of time in seconds that a session should be valid for. Defaults to 31536000 seconds (1 year).
 * `revokeSessionOnPasswordReset` - When a user changes their password, either through the reset password email or while logged in, all sessions are revoked if this is true. Set to false if you don't want to revoke sessions.
 * `accountLockout` - Lock account when a malicious user is attempting to determine an account password by trial and error.
+* `passwordPolicy` - Optional password policy rules to enforce.
 
 ##### Logging
 
@@ -277,6 +278,18 @@ var server = ParseServer({
     duration: 5, // duration policy setting determines the number of minutes that a locked-out account remains locked out before automatically becoming unlocked. Set it to a value greater than 0 and less than 100000.
     threshold: 3, // threshold policy setting determines the number of failed sign-in attempts that will cause a user account to be locked. Set it to an integer value greater than 0 and less than 1000.
   },
+  // optional settings to enforce password policies
+  passwordPolicy: {
+    // Two optional settings to enforce strong passwords. Either one or both can be specified. 
+    // If both are specified, both checks must pass to accept the password
+    // 1. a RegExp representing the pattern to enforce 
+    validatorPattern: /^(?=.*[a-z])(?=.*[A-Z])(?=.*[0-9])(?=.{8,})/, // enforce password with at least 8 char with at least 1 lower case, 1 upper case and 1 digit
+    // 2. a callback function to be invoked to validate the password  
+    validatorCallback: (password) => { return validatePassword(password) }, 
+    doNotAllowUsername: true, // optional setting to disallow username in passwords
+    //optional setting to set a validity duration for password reset links (in seconds)
+    resetTokenValidityDuration: 24*60*60, // expire after 24 hours
+  }
 });
 ```