BoardTest doesn't clean up after itself
The BoardTest class creates a TextFile.txt whenever the tests are run. Having a JUnit test interact with the filesystem is not something that should happen.
I propose that these test use an OutputStream rather than a filename, like in this example:
final ByteArrayOutputStream out = new ByteArrayOutputStream();
final PrintStream printStream = new PrintStream(out);
stack.readInput(printStream, in);
assertEquals("253", out.toString());