Use new RSpec 'expect' syntax in README example

Wisper looks great, I'm looking forward to using it on a project soon!
Merge pull request #59 from andyw8/patch-1

Use new RSpec 'expect' syntax in README example
added custom rspec matcher
Move spec for rspec stubbing in to correct directory with better filename
bump rspec version, add rake as development dependency
Add CHANGELOG #61 [skip ci]
Merge pull request #69 from krisleech/update-dependencies

bump rspec version, add rake as development dependency
Merge pull request #68 from krisleech/write-a-changelog-61

Add CHANGELOG #61 [skip ci]
Update the README to use Ruby 2 style Hash (FIX #65)
Merge pull request #70 from artmees/master

Update the README to use Ruby 2 style Hash [#65]
Allow invocation of event to be changeable [wip] [#38]
tidy up spec for send invoker [#38]
Add a logger invoker
use `anything` instead of `nil` in spec where value does not matter