Handle gulp-mocha error when `gulp watch`

gulp-mocha throw error when test fails, but this repos' gulpfile does
not handle error, then gulp-watch aborts.

Unhandled 'error' event
https://gist.github.com/sanemat/534c65b722d1e0bb91c7

I added error handler like stackoverflow's solution.

related resources:
http://stackoverflow.com/questions/21602332/catching-gulp-mocha-errors
Failing tests causes gulp watch process to terminate sindresorhus/gulp-mocha
https://github.com/sindresorhus/gulp-mocha/issues/5
https://github.com/gulpjs/gulp/blob/master/docs/recipes/mocha-test-runner-with-gulp.md
add jshint comment to supress warning
Merge branch 'sanemat-fix/catch-error-for-watch'

* sanemat-fix/catch-error-for-watch:
  add jshint comment to supress warning
  Handle gulp-mocha error when `gulp watch`
add plumber to handle mocha error
add plumber to generated project
Remove unused variable
Fix bump task

Add and implement gulp-util
Change command-line parameter to --type

Use:
gulp bump --type (major|minor|patch|prerelease)
Fix bump task for main project
Merge branch 'kojiwakayama-master'

* kojiwakayama-master:
  Fix bump task for main project
  Fix bump task
bump version
add mocha globals
Fix istanbul test
Update badge urls
Avoid multiple line break

At initial prompt, I don't choice release module, then I met
gulp-jscs 'Multiple line break error', so I replace gulp task order.
Add linebreaks in gulpfiles
Merge branch 'sanemat-fix/remove-unnecessary-new-line'

* sanemat-fix/remove-unnecessary-new-line:
  Add linebreaks in gulpfiles
  Avoid multiple line break
Remove deprecated gulp.run()

I met this warning:
gulp.run() has been deprecated. Use task dependencies or gulp.watch task
triggering instead.

See below:
https://github.com/gulpjs/gulp/blob/master/docs/recipes/running-tasks-in-series.md
Merge pull request #14 from sanemat/fix/remove-deprecation

Remove deprecated gulp.run()
remove require comments
bump version