Create test_thermal.py

Allow rtdtemp without rounding

Author: marcostfermin

test/test_thermal.py

@@ -0,0 +1,6 @@
+import electricpy.thermal as thermal
+
+
+def test_rtdtemp_allows_no_rounding():
+    temp = thermal.rtdtemp(100.0, rtdtype="PT100", round=None)
+    assert isinstance(temp, float)