Add Flux from() and filter() methods

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

src/QueryBuilder.php

@@ -0,0 +1,57 @@
+<?php
+
+namespace Arendsen\FluxQueryBuilder;
+
+class QueryBuilder {
+
+    /**
+     * @var array $from
+     */
+    private $from;
+
+    /**
+     * @var string $measurement
+     */
+    private $measurement;
+
+    /**
+     * @var array $range
+     */
+    private $range;
+    
+    public function from(array $from): QueryBuilder
+    {
+        $this->from = $from;
+        return $this;
+    }
+
+    public function fromBucket(string $bucket): QueryBuilder {
+        $this->from = ['bucket' => $bucket];
+        return $this;
+    }
+
+    public function fromMeasurement(string $measurement): QueryBuilder
+    {
+        $this->measurement = $measurement;
+        return $this;
+    }
+
+    public function addRange(array $range): QueryBuilder
+    {
+        $this->range = $range;
+        return $this;
+    }
+
+    public function addRangeStart(string $rangeStart): QueryBuilder
+    {
+        $this->range = ['start' => $rangeStart];
+        return $this;
+    }
+
+    public function build(): string
+    {
+        //TODO: build the query dynamically here
+        return 'from(bucket: "test_bucket", host: "host", org: "example-org", token: "token") |> ';
+    }
+
+}