Get rid of duke.properties in favour of the manifest

[larsga]

The jar file manifest contains the same information, so there's really no reason to maintain the duke.properties file. However, getting rid of it is a little harder than it seems, because the integration tests need it. Line 163 in IT.java fails if we remove duke.properties:

  private Result runjava(String klass, String args) throws IOException {
    String jar = "target/duke-" + Duke.getVersion() + ".jar"; // THIS IS LINE 163
    String cmd = "java -cp " + jar + " no.priv.garshol.duke." + klass +
                  " " + args;
    return run(cmd);
  }

A branch named pull-155 has been created to work on this and the work is completed there except for this one issue.

[ztsmith]

This file has been causing me issues. I wasn't able to export a runnable JAR and have the duke.properties file included in the main class hierarchy. It got added underneath the resources path instead. I got it to work by opening up the JAR as a zip and just moving the file. Is there something special I need to do to have it included in the JAR export (using eclipse)?