Added unittest for squareRootFunction

src/test/c/test_taschenrechner.c

@@ -109,5 +109,10 @@ void test_ConTime(void) {//5 ms to s
 }
 
 
+// Square root function
+void test_squareRootFunction(void) {
+    TEST_ASSERT_EQUAL_FLOAT(2.0, squareRootFunction(4.0));
+}
+
 
 #endif // TEST