Add features from README

logrus.go

@@ -1,24 +1,19 @@
 package logrus
 
-import ()
-
-// TODO: Type naming here feels awkward, but the exposed variable should be
-// Level. That's more important than the type name, and libraries should be
-// reaching for logrus.Level{Debug,Info,Warning,Fatal}, not defining the type
-// themselves as an int.
-type LevelType uint8
 type Fields map[string]interface{}
 
+type LevelType uint8
+
 const (
 	LevelPanic LevelType = iota
 	LevelFatal
-	LevelWarning
+	LevelError
+	LevelWarn
 	LevelInfo
 	LevelDebug
 )
 
 var Level LevelType = LevelInfo
-var Environment string = "development"
 
 // StandardLogger is what your logrus-enabled library should take, that way
 // it'll accept a stdlib logger and a logrus logger. There's no standard