Replace sync methods calls with async analogs (#1457)

Replace sync methods calls with async analogs

Author: DamirAinullin

Dapper.Contrib/SqlMapperExtensions.Async.cs

@@ -313,7 +313,7 @@ public static async Task<bool> DeleteAsync<T>(this IDbConnection connection, T e
             sb.AppendFormat("DELETE FROM {0} WHERE ", name);
 
             var adapter = GetFormatter(connection);
-            
+
             for (var i = 0; i < allKeyProperties.Count; i++)
             {
                 var property = allKeyProperties[i];
@@ -379,7 +379,7 @@ public async Task<int> InsertAsync(IDbConnection connection, IDbTransaction tran
         var cmd = $"INSERT INTO {tableName} ({columnList}) values ({parameterList}); SELECT SCOPE_IDENTITY() id";
         var multi = await connection.QueryMultipleAsync(cmd, entityToInsert, transaction, commandTimeout).ConfigureAwait(false);
 
-        var first = multi.Read().FirstOrDefault();
+        var first = await multi.ReadFirstOrDefaultAsync().ConfigureAwait(false);
         if (first == null || first.id == null) return 0;
 
         var id = (int)first.id;
@@ -531,7 +531,7 @@ public async Task<int> InsertAsync(IDbConnection connection, IDbTransaction tran
         var cmd = $"INSERT INTO {tableName} ({columnList}) VALUES ({parameterList}); SELECT last_insert_rowid() id";
         var multi = await connection.QueryMultipleAsync(cmd, entityToInsert, transaction, commandTimeout).ConfigureAwait(false);
 
-        var id = (int)multi.Read().First().id;
+        var id = (int)(await multi.ReadFirstAsync().ConfigureAwait(false)).id;
         var pi = keyProperties as PropertyInfo[] ?? keyProperties.ToArray();
         if (pi.Length == 0) return id;