Fix gorp to internally lowercase fields for Postgres

Postgres folds all unquoted column names to lowercase, and doing this
allows that to work nicely without screwing up the queries for the other
database engines.

internal/handlers/handlers.go

@@ -1,7 +1,7 @@
 package handlers
 
 import (
-	"gopkg.in/gorp.v2"
+	"github.com/aclindsa/gorp"
 	"log"
 	"net/http"
 	"path"

internal/handlers/tx.go

@@ -2,7 +2,7 @@ package handlers
 
 import (
 	"database/sql"
-	"gopkg.in/gorp.v2"
+	"github.com/aclindsa/gorp"
 	"strings"
 )