added support for skos:inScheme
prerequisites for an editable Concept::SKOS::Scheme singleton

edit form is still missing, though
top term support for skos importer

closes #135
added missing quote
fixed typo
improved error message
editable concept scheme
editable concept scheme
finished editable concept scheme

tests still red, though
only redeclare top concepts after scheme has been updated

tests are green again
test coverage for concept scheme
Merge branch 'master' of github.com:innoq/iqvoc