Fix filter-date format & add test for filter-date

src/test/java/at/pcgamingfreaks/mkvaudiosubtitlechanger/config/PicoCliTest.java

@@ -0,0 +1,23 @@
+package at.pcgamingfreaks.mkvaudiosubtitlechanger.config;
+
+import at.pcgamingfreaks.mkvaudiosubtitlechanger.impl.CommandRunner;
+import at.pcgamingfreaks.mkvaudiosubtitlechanger.impl.validation.ValidationExecutionStrategy;
+import org.junit.jupiter.api.Test;
+import picocli.CommandLine;
+
+import java.time.Instant;
+
+import static at.pcgamingfreaks.mkvaudiosubtitlechanger.util.PathUtils.TEST_FILE;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class PicoCliTest {
+
+    @Test
+    void loadFilterDate() {
+        CommandRunner underTest = new CommandRunner();
+        new CommandLine(underTest)
+                .setExecutionStrategy(new ValidationExecutionStrategy())
+                .parseArgs("-d", "2012-12-12T12:12:12.00Z", TEST_FILE);
+        assertEquals(Instant.parse("2012-12-12T12:12:12.00Z"), underTest.getConfig().getFilterDate());
+    }
+}