Quang Tam Le

Hi everyone, I can not download the iosxrv-fullk9-x64.iso so that I can do run the vagrant. Is there any way I can download it ??? Thank you in advances

Fix typos for PRE and POST keys in the node_value_passed of not_exists operator

1

### Description of Issue/Question According to the [code](https://github.com/Juniper/jsnapy/blob/master/lib/jnpr/jsnapy/operator.py#L563): PRE and POST keys in the **node_value_passed** dict of **not_exists** operator are capitalized which are not synchronized (should be in small letters...