Cleaned up and add mysql test

Author: Michel Bieleveld

QueryBuilder.Tests/MySqlExecutionTest.cs …uilder.Tests/MySql/MySqlExecutionTest.csQueryBuilder.Tests/MySqlExecutionTest.cs renamed to QueryBuilder.Tests/MySql/MySqlExecutionTest.cs QueryBuilder.Tests/MySqlExecutionTest.cs renamed to QueryBuilder.Tests/MySql/MySqlExecutionTest.cs

@@ -213,12 +213,12 @@ public void BasicSelectFilter()
                 // 2020
                 {"2020-01-01", 10},
                 {"2020-05-01", 20},
-                
+
                 // 2021
                 {"2021-01-01", 40},
                 {"2021-02-01", 10},
                 {"2021-04-01", -10},
-                
+
                 // 2022
                 {"2022-01-01", 80},
                 {"2022-02-01", -30},
@@ -251,10 +251,11 @@ public void BasicSelectFilter()
 
         QueryFactory DB()
         {
-            var host = System.Environment.GetEnvironmentVariable("SQLKATA_MYSQL_HOST");
-            var user = System.Environment.GetEnvironmentVariable("SQLKATA_MYSQL_USER");
-            var dbName = System.Environment.GetEnvironmentVariable("SQLKATA_MYSQL_DB");
-            var cs = $"server={host};user={user};database={dbName}";
+            var host = System.Environment.GetEnvironmentVariable("SQLKATA_MYSQL_HOST") ?? "localhost";
+            var user = System.Environment.GetEnvironmentVariable("SQLKATA_MYSQL_USER") ?? "root";
+            var password = System.Environment.GetEnvironmentVariable("SQLKATA_MYSQL_PASSWORD") ?? "my-secret-pw";
+            var dbName = System.Environment.GetEnvironmentVariable("SQLKATA_MYSQL_DB") ?? "test";
+            var cs = $"server={host};user={user};database={dbName};password={password}";
 
             var connection = new MySqlConnection(cs);
 
@@ -266,4 +267,4 @@ QueryFactory DB()
 
 
     }
-}
+}