Add dependency check for python-jmespath on Debian based systems.

[CaptainFluffyToes]

I received the error:

TASK [conjurConfig : Get full name of conjur-appliance image] ******************************************************************************************************
task path: /mnt/hgfs/GitHubProjects/cdemo/conjurDemo/roles/conjurConfig/tasks/conjurEE.yml:20
fatal: [default]: FAILED! => {
    "msg": "You need to install \"jmespath\" prior to running json_query filter"
}
        to retry, use: --limit @/mnt/hgfs/GitHubProjects/cdemo/conjurDemo/site.retry

PLAY RECAP *********************************************************************************************************************************************************
default                    : ok=24   changed=5    unreachable=0    failed=1

This error seems to point to a python dependency that is missing on my system. I am using TurnKey Linux Core which is a Debian Jessie based distribution.

The error can be solved by running: apt-get install python-jmespath

There should be a check on debian based systems for this particular package and then added as an automatic install.