Remove reference to obsolete jscoverage in comments
Mention coverage_html_dir option in README
Abstract location of coverage binary
Only attempt to generate coverage reports if istanbul is available
Spec out case where istanbul binary is missing
Merge remote-tracking branch 'origin/pr/146'
Update CHANGELOG.
Release 1.18.3
Fix typo in JasmineRails mount point
change run_on_change to run_on_modifications

As vim has a little bit different style of saving files, it had been triggering guard 3 times in a row with "run_on_change".
Update specs and docs.
Use double() instead of mock()
Remove ruby GNTP.
Get rid of 1.8 Hash style options.
Inherit from Guard::Plugin
Update CHANGELOG.
Fix Guard::Jasmine initialization.
Require correct plugin base class.
ability to provide line number for spec

in the same manner as rspec, the line number may be provided directly after the
file name or by explicitely passing a cli argument
don't add up all 'it' examples