simmer 3.6.2

Minor changes and fixes:

• Update "The Bank Tutorial: Part I" vignette (@nacnudus in #90).
• Fix trap()'s handler cloning and associated test (#91).
• Apply select()'s policy also when resources is a function (#92).
• Accept dynamic timeouts in batches (#93).
• Change rollback()'s default behaviour to times=Inf, i.e., infinite loop (#95).
• Stop and throw an error when timeout() returns a missing value (#96 and #97).
• Fix memory management: resetting the environment was clearing but not deallocating memory (#98, fixed in #99).
• Fix object destruction: workaround for tidyverse/magrittr#146 (#98, fixed in effcb6b).