add test for sensor_name and sensor_unit

test/sensors_test.gleam

@@ -0,0 +1,19 @@
+import gleeunit
+import gleeunit/should
+import sensors
+
+pub fn main() -> Nil {
+  gleeunit.main()
+}
+
+// gleeunit test functions end in `_test`
+pub fn file_read_test() {
+  let reading =
+    sensors.sensor_name(sensors.Temperature)
+    <> " "
+    <> "20.5"
+    <> " "
+    <> sensors.sensor_unit(sensors.Temperature)
+  reading
+  |> should.equal("Temperature 20.5 °C")
+}