Delete an unused test file.

Factor the logic for parsing a double from a GheoNet specification in order to isolate it
and use it where necessary.

Prepared a test for simple network in order to be complete tomorrow with Fabio.
Prepared the tests for splitted GheoNet specification containing nodes with load gadgets
that end up with negative pressures.
Prepared the assertions for the ring network.
Prepared the tests for the three node network, splitting in three new files. Two of
them (one with manual mutations, one with repeat until without negative pressure check)
needs update on the network because the current one is a configuration to force nodes with
load gadget to have negative pressure.