update DB::ExecResult#rows_affected to Int64

spec/custom_drivers_types_spec.cr

@@ -70,7 +70,7 @@ class FooDriver < DB::Driver
     end
 
     protected def perform_exec(args : Enumerable) : DB::ExecResult
-      DB::ExecResult.new 0, 0i64
+      DB::ExecResult.new 0i64, 0i64
     end
   end
 
@@ -124,7 +124,7 @@ class BarDriver < DB::Driver
     end
 
     protected def perform_exec(args : Enumerable) : DB::ExecResult
-      DB::ExecResult.new 0, 0i64
+      DB::ExecResult.new 0i64, 0i64
     end
   end
 

spec/dummy_driver.cr

@@ -49,7 +49,7 @@ class DummyDriver < DB::Driver
 
     protected def perform_exec(args : Enumerable)
       set_params args
-      DB::ExecResult.new 0, 0_i64
+      DB::ExecResult.new 0i64, 0_i64
     end
 
     private def set_params(args)

src/db.cr

@@ -78,7 +78,7 @@ module DB
   {% end %}
 
   # Result of a `#exec` statement.
-  record ExecResult, rows_affected : Int32, last_insert_id : Int64
+  record ExecResult, rows_affected : Int64, last_insert_id : Int64
 
   # :nodoc:
   def self.driver_class(driver_name) : Driver.class