Inline Repository#relation functionality

Previously, relation instantiation was done in
subclasses so this method made sense. As this is
not needed anymore, inlining the method seems to
be ok. This also kills a reek data clump warning
where [name, header] have been taken to 3 methods.
Add module comment for Veritas::Adapter::DataObjects
Avoid DuplicateMethodCall in Veritas::Adapter.get
Import latest support/options from dkubb/axiom-types

As a bonus, this fixes a NilCheck warning in reek
Fix UncommunicativeVariableName in graphviz code
Make Graphviz#{label, edge_options} class methods

Fixes UtilityFunction and FeatureEnvy warnings
Rename Support::Graphviz#{map => node_map}

Also exclude this from reek's duplicate method call
checks. Since reek only supports excluding "raw"
method names, I had to rename the method before I
wanted to exclude it, as I'm not sure that I would
want Enumerable#map to be allowed to be called more
than once per method.

So after all, reek's weakness (not allowing fully
qualified method names) turned out to help me find
a bad name to begin with.