Improves documentation (#13)

* Documents all env variables and adds an example project

* Adds godoc comments

* Fixed package naming issue

models/session.go

@@ -5,6 +5,7 @@ import (
 	"time"
 )
 
+// Session holds information about user sessions and when they expire
 type Session struct {
 	gorm.Model
 	Identifier string
@@ -12,6 +13,7 @@ type Session struct {
 	ExpiresAt  time.Time
 }
 
+// HasExpired is a helper function that checks if the current time is after the session expire datetime
 func (s Session) HasExpired() bool {
 	return s.ExpiresAt.Before(time.Now())
 }