add shared module and make energy transformation subclass of transformation

[akleinau]

closes #435

• adds shared module "oeo-shared" which will provide all classes needed in all other edit modules, as well as imports like bfo, iao-annotation and ro.
• rewrites the imports of the other modules accordingly.
• moves "Transformation" into this module
• makes "energy transformation" subclass of "transformation"

Maybe the description of the new module can be refined?

[akleinau]

@jannahastings @MGlauer unfortunately the transformation class in the new module has a "http://openenergy-platform.org/ontology/oeo" identifier and therefore travis thinks it has no label when it's imported into oeo-physical (bc the label is in oeo-shared).
Which means our ontology runs perfectly right now but the tests fail.

[jannahastings]

@MGlauer Is it possible for the tests to run robot merge to combine the different OEO modules, before checking the labels?

[jannahastings]

This is great. Also in the future we can move some of our object properties into the shared module (e.g. "uses" I think is used in different modules) -- but that should be part of a separate issue and later PR.