Remove extraneous @@mysql.nil? test.
assert_equal(false, ...) is better written as refute(); and assert_equal(true, ...) is better written as assert().
DRY up the code for WCPGW::Store::Environment.load_by_{id,name}.
DRY up the code for WCPGW::Store::Release.{all,load_by_id}.
Drop usage of Proc.new -- trivial performance gain not worth possible confusion when reading the code.
Remove full qualification of names where possible; depend on ruby to figure it out.
Centralize and simplify access to Backend.connection.