Error was introduced in d1fe23d8a0

* seismosizer.ellipsoid: initial commit

* model.event: Event inheriting from Location

* seismosizer: added CLVDVolumeSource

* Event inheriting from Location (#340)

* explosion_source: bugfix deflation volume src

* docs: typo in crust2x2 example

* model.gnss: correlation factor defaulting to 0.

* automap: improving gnss campaing plot

* model.event: Event inheriting from Location

* model.event: reduce float precision on hashing

* scenario.waveform: avoid repeated target setup

* scenario: save markers to meta path

* scenario: skip traces if segments aren't overlapping

* added doc string

* explosion_source: bugfix deflation volume src

* docs: typo in crust2x2 example

* model.gnss: correlation factor defaulting to 0.

* automap: improving gnss campaing plot

* model.event: Event inheriting from Location

It is now possible to add a list of custom tags to the event object, e.g.

    event.tags = ['cluster:A', 'result:unstable']

The format of the tags must be '<key>:<value>' where the characters in
the <key> and <value> parts are restricted by the regular expression
r'^[A-Za-z][A-Za-z0-9._]{0,128}:[A-Za-z0-9._-]+$'.