[WFLY-2820] Support for Properties File in wildfly-arquillian-container-managed

	modified:   arquillian/container-managed/src/main/java/org/jboss/as/arquillian/container/managed/ManagedContainerConfiguration.java
	modified:   arquillian/container-managed/src/main/java/org/jboss/as/arquillian/container/managed/ManagedDeployableContainer.java
	modified:   arquillian/container-managed/src/test/java/org/jboss/as/arquillian/container/managed/IntegrationTestCase.java
	modified:   arquillian/container-managed/src/test/resources/arquillian.xml
	new file:   arquillian/container-managed/src/test/resources/testfile.properties