add temperature conversion

src/Temperature.php

@@ -0,0 +1,23 @@
+<?php
+
+namespace KbhandariWeb\UnitConversions;
+
+class Temperature
+{
+    private float $celsius;
+
+    public static function forCelsius(float $celsius): self
+    {
+        return new static($celsius);
+    }
+
+    public function __construct(float $celsius)
+    {
+        $this->celsius = $celsius;
+    }
+
+    public function toFahrenheit(): float
+    {
+        return ($this->celsius * 1.8) + 32;
+    }
+}

tests/TemperatureTest.php

@@ -0,0 +1,17 @@
+<?php
+
+namespace KbhandariWeb\UnitConversions\Tests;
+
+use PHPUnit\Framework\TestCase;
+use KbhandariWeb\UnitConversions\Temperature;
+
+class TemperatureTest extends TestCase
+{
+    /** @test */
+    public function it_can_convert_celsius_to_fahrenheit()
+    {
+        $fahrenheit = Temperature::forCelsius(100)->toFahrenheit();
+
+        $this->assertEquals(212, $fahrenheit );
+    }
+}