Refactor Devtools::Project#assert_within_timeout to be simpler
Refactor Devtools::Project#assert_within_timeout to be simpler

* Change to use the `Benchmark::Tms#total` method which is exactly
  the same as the code it replaced.
JonathonMA/devtools,zaidan/devtools,mvz/devtools,mbj/devtools,backus/devtools,sferik/devtools