Add FIXMEs
Only attempt to load coveralls on CI
Unref GObject::Object in finalizer

* Unref objects created in constructors, unless refcount is already at
  zero or clearly wrong
* Avoid refcount dropping to zero in specs
* Add FIXMEs
Make GObject::Object#ref work
Increase refcount for :object arguments with full ownership transfer
Make argument obligatory
Let ReturnValueInfo know about ownership_transfer
Increase refcount for :object return values of vfuncs with full transfer
Loosen ref_count check

Older versions of gobject_introspection incorrectly did not unref the
argument to gi_marshalling_tests_object_full_inout, causing the
ref_count to remain 2.
Dereference GObjects in finalizer [merges 'unref-objects']
Enforce argument alignment
Refactor FieldBuilder to avoid trailing whitespace
Clean up new offenses
Apply more RuboCop rules [merges 'apply-rubocop']
Update changelog