reference global logrus (#274)

* reference logrus' global logger instead of passing and storing a logger reference everywhere

* always directly use global logrus logger instead of referencing an instance

* test suites should also directly use the global logrus logger

* rename gin logging function to clarify that it's middleware

* correct comments which erroneously referenced removed logger parameter

* setting log level for tests now uses logrus' exported type instead of the string value, to guarantee error isn't possible

testrig/federatingdb.go

@@ -7,5 +7,5 @@ import (
 
 // NewTestFederatingDB returns a federating DB with the underlying db
 func NewTestFederatingDB(db db.DB) federatingdb.DB {
-	return federatingdb.New(db, NewTestConfig(), NewTestLog())
+	return federatingdb.New(db, NewTestConfig())
 }