refactors data access layer to use pop ORM for eager loading, adds book titles rented to renters in response body

bookish-server/mysql/mysql.go

@@ -1,19 +1,19 @@
 package mysql
 
 import (
-	"github.com/jmoiron/sqlx"
+	"github.com/gobuffalo/pop"
 )
 
 // store holds a connection to the application database.
 type store struct {
-	*sqlx.DB
+	*pop.Connection
 }
 
 // NewStore creates a new connection to the database and returns a store containing the connection.
 func NewStore(dsn string) (s *store, err error) {
-	db, err := sqlx.Open("mysql", dsn)
+	db, err := pop.Connect("development")
 	if err != nil {
-		return s, err
+		return &store{}, err
 	}
 
 	return &store{db}, nil