trajectory/ballistics/calculators/BCResultTest: Added unit test

lib/src/test/java/org/fairportrobotics/frc/robolib/trajectory/ballistics/calculators/BCResultTest.java

@@ -0,0 +1,12 @@
+package org.fairportrobotics.frc.robolib.trajectory.ballistics.calculators;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+public class BCResultTest {
+    @Test static void testIsValid() {
+        assertTrue(new BCResult(1.0, null).isValid(), "Valid penalty");
+        assertFalse(new BCResult(null, null).isValid(), "Invalid penalty");
+    }
+}