update: changing setup

Closes #4

See merge request !1

- allow passing configuration to agents
  - friendly name
  - task directory
  - temp directory
  - backend host
- fix example configuration
- add session key configuration
- update ldap_auth plugin
  - changes to default ldap plugin are:
    - attribute mapping
    - bind dn and password

Python 3.5 -> 3.6
INGInious 0.6 -> 0.7
secret_key in session_parameters

Fixes #3

when schema is known results are strings not lists

includes custom fixes/improvements such as automatic setting of username

This reverts commit bd808b39.

This reverts commit e9c0856f.

it has breaking changes in 1.0

- add lighttpd server
- run as fastcgi
- remove docker client

remove unnecessary authentication