finished both exceptions.

src/main/java/ch/zhaw/pm2/racetrack/InvalidFileFormatException.java

@@ -1,5 +1,8 @@
 package ch.zhaw.pm2.racetrack;
 
 public class InvalidFileFormatException extends Exception {
-    // TODO: implementation
+
+    public InvalidFileFormatException(String errorMessage) {
+        super(errorMessage);
+    }
 }

src/main/java/ch/zhaw/pm2/racetrack/InvalidTrackFormatException.java

@@ -1,5 +1,7 @@
 package ch.zhaw.pm2.racetrack;
 
 public class InvalidTrackFormatException extends Exception {
-    // TODO: implementation
+    public InvalidTrackFormatException(String errorMessage) {
+        super(errorMessage);
+    }
 }