Changed Pipeline relationships to OneToOne not foreign key, because it's
more accurate
Removed test database from Git cos it shouldn't be in there
Refactored and moved around until the pipeline test works again

Now Pipelines keep the built-up SVG files
Added in a sketch of a COSMEndpoint, which uses slightly hacky POST
stuff to receive data, and forward it on to a linked DataStore. Can now
(theoretically) trigger sending stuff based on cosm triggers.
Added ability for COSMEndpoints to set/remove their triggers on COSM