#108 Refactored test code for loading JavaViews. Added a type check to the JavaViewLoader so that a useful exception is thrown when the view class doesn't subclass from javafx.scene.Parent.
#108 refactored ViewLoader tests for FxmlViews. Removed ViewLoaderIntegrationTest as the test cases are better places in the specific test classes for JavaViews and FxmlViews.
#108 small refactoring of FluentViewLoaderTest.
Merge pull request #111 from sialcasa/#108_test_refactoring

#108 test refactoring

Now tests aren't depending on specific implementation details of the view loading process anymore.