Add Map expression

Signed-off-by: davidarendsen <davidarendsen@hey.com>

tests/Expression/KeyValueTest.php

@@ -1,36 +0,0 @@
-<?php
-
-declare(strict_types=1);
-
-namespace Tests\Expression;
-
-use Exception;
-use Arendsen\FluxQueryBuilder\Expression\KeyValue;
-use PHPUnit\Framework\TestCase;
-
-final class KeyValueExpressionTest extends TestCase
-{
-    public function testSimpleKeyvalue()
-    {
-        $keyvalue = KeyValue::setEqualTo('_measurement', 'test_measurement')
-            ->andEqualTo('_field', 'user')
-            ->or('count', '>=', '1')
-            ->and('user', KeyValue::EQUAL_TO, 'my_username')
-            ->orNotEqualTo('test', 'world');
-
-        $query = 'r._measurement == "test_measurement" and r._field == "user" or ' .
-            'r.count >= "1" and r.user == "my_username" or r.test != "world"';
-
-        $this->assertEquals($keyvalue->__toString(), $query);
-    }
-
-    public function testInvalidOperator()
-    {
-        $this->expectException(Exception::class);
-
-        KeyValue::set('_measurement', '9dkda9e', 'test_measurement')
-            ->andEqualTo('_field', 'user')
-            ->or('_field', '==', 'field2')
-            ->andEqualTo('user', 'my_username');
-    }
-}