Integrate validator

[eFrane]

Integrate OParl/validator into the website. This is depends on #29,
because we can't run the validator without liboparl present.

The validation flow on the website should be as follows:

1. A user enters an endpoint url to be validated and an email
   address at which they want to be notified once validation
   completes.
2. The information is enqueued and eventually processed by
   a validation job
3. The results of the validation are stored for further processing
   and formatted into a neat email for the customer.

[eFrane]

This is technically done but currently in reconsideration since the actual server load for running the validator goes way over the expected load.

[eFrane]

Status Update:

The validator will be provided as a dockerized flask application which will do the heavy lifting. This also means that this issue is no longer related to #29.

Development of the afore mentioned application can be followed at OParl/validator-api.