upgrade vs version and add unit test

Bump version 1.1.6

add unit tests.

remove unused override method ToString.

modify code comment.

add code comments.

add more job test.

Throws exception when json file is null or empty.

edit readme.

add code comments.

Breaking changes: Persists job data to storage with associated RecurringJob.

resolve dependencies to "Hangfire.RecurringJobExtensions": "1.1.4-*"

edit readme

fix issue 1->RecurreingJobAttribute timezoneInfo not supported

Creates job data instance into PerformContext if job data not exist .