Merge pull request #62 from ThomasSevestre/master

add option to specify exception to catch
add Thomas Sevestre to contributors list
remove trailing white space
implement Rufus::Scheduler.new

So that rufus-scheduler 3.0 quickstarts are OK with 2.0.20
release 2.0.20
add license to gemspec file

closes gh-64
release 2.0.21
add spec for "cannot parse '/10'"

fighting gh-65
sync Gemfile.lock
parse "/10 * * * *" again (like <= 2.0.19 did)

thanks @skrd

closes gh-65
release 2.0.22
fix timeouts issues with jobs waiting for a mutex
Merge pull request #67 from kratob/two

fix timeout issue when using mutexes
list Tobias "kratob" Kraze as contributor
release 2.0.23
lowered tzinfo to >= 0.3.22
release 2.0.24
add spec for "00 00 * * *"