Add Melissa (HVAC/climate) component (#11503)

* Adding component melissa

* Adding sensor component melissa

* Adding Melissa climate component

* Testing component

* Tests for Climate component

* Testing Melissa sensor

* Fixing review Thank you @rytilahti

tests/components/test_melissa.py

@@ -0,0 +1,38 @@
+"""The test for the Melissa Climate component."""
+import unittest
+from tests.common import get_test_home_assistant, MockDependency
+
+from homeassistant.components import melissa
+
+VALID_CONFIG = {
+    "melissa": {
+        "username": "********",
+        "password": "********",
+    }
+}
+
+
+class TestMelissa(unittest.TestCase):
+    """Test the Melissa component."""
+
+    def setUp(self):  # pylint: disable=invalid-name
+        """Initialize the values for this test class."""
+        self.hass = get_test_home_assistant()
+        self.config = VALID_CONFIG
+
+    def tearDown(self):  # pylint: disable=invalid-name
+        """Teardown this test class. Stop hass."""
+        self.hass.stop()
+
+    @MockDependency("melissa")
+    def test_setup(self, mocked_melissa):
+        """Test setting up the Melissa component."""
+        melissa.setup(self.hass, self.config)
+
+        mocked_melissa.Melissa.assert_called_with(
+            username="********", password="********")
+        self.assertIn(melissa.DATA_MELISSA, self.hass.data)
+        self.assertIsInstance(
+            self.hass.data[melissa.DATA_MELISSA], type(
+                mocked_melissa.Melissa())
+        )