Fixes failing start up because of no longer existent
`security.guest.lecturer.enabled` setting.

Extend API and config to support auth services per role



See merge request !22

evict session cache both for session entries in the cache (https://github.com/th…

…m-projects/arsnova-backend/wiki/Caching  <-- see List of cache entries and associated keys)

See merge request !20

(https://github.com/thm-projects/arsnova-backend/wiki/Caching
^-- see List of cache entries and associated keys)

add bulk save method for questions (for importing via csv)

This merge request adds a bulk save function for questions. For now, it's only used for the question import via csv to not save every single question with a seperate request.

See merge request !19

In some cases the Socket.IO servers used in test cases are not closed
when starting a new test. In this cases the tests will fail with
an address conflict because an other Socket.IO server is still running.

Using a new port, starting with previous defined port 1234 up to 1243 will
assign every new created Socket.IO server an other address/port.

An address conflict will still occure if an other service is running on
ports from 1234 to 1243, so it is generally a bad idea to have tests in the
hope that no side effects will occure from outside of application scope.

Closes GH-34

In some cases the Socket.IO servers used in test cases are not closed
when starting a new test. In this cases the tests will fail with
an address conflict because an other Socket.IO server is still running.

Using a new port, starting with previous defined port 1234 up to 1243 will
assign every new created Socket.IO server an other address/port.

An address conflict will still occure if an other service is running on
ports from 1234 to 1243, so it is generally a bad idea to have tests in the
hope that no side effects will occure from outside of application scope.

* Fail build on HTTP upload errors
* Undeploy application before deployment
* Fix Tomcat deployment path

Fix session export

fixes the import of sessionFeatures and messages of the day.

See merge request !18