Added a set of "try" prefixed constructors to secret types that can return an Err if memory locking fails. The non-"try" prefixed constructors will panic in the event of a memory locking failure.
Changed tests to use the non-"try_" prefixed constructors, because tests should be run with MLOCK_SECRETS=false and never fail for mlock related reasons.
Improved the docstrings for secret-type constructors to differentiate those that panic from those that return an Err.
Errif memory locking fails. The non-"try" prefixed constructors will panic in the event of a memory locking failure.MLOCK_SECRETS=falseand never fail formlockrelated reasons.Err.Closes issue #6