code: function bumpVersion(importance){
  	return function bump_version (done){
  		if (!importance) throw new Error(`
    An importance must be specified for a version bump to occur.
    Valid importances: "--patch", "--minor", "--major"
  `);
  		// get all the files to bump version in
  		return gulp.src('./package.json')
  			// bump the version number in those files
  			.pipe(bump({type: importance}))
  			// save it back to filesystem
  			.pipe(gulp.dest('./'))
  			//commit the changed version number
  			.pipe(git.commit(`${importance} version bump`))
  	}
  }
docs: Bump up the current version number