provider/google: drop the account file.

This was already marked as removed, but the way the provider handled it,
people were still being prompted for input anyways. This removes it from
the provider entirely, so people won't be prompted for input.

builtin/providers/google/provider.go

@@ -15,13 +15,6 @@ import (
 func Provider() terraform.ResourceProvider {
 	return &schema.Provider{
 		Schema: map[string]*schema.Schema{
-			"account_file": &schema.Schema{
-				Type:        schema.TypeString,
-				Optional:    true,
-				DefaultFunc: schema.EnvDefaultFunc("GOOGLE_ACCOUNT_FILE", nil),
-				Removed:     "Use the credentials field instead",
-			},
-
 			"credentials": &schema.Schema{
 				Type:     schema.TypeString,
 				Optional: true,