Upgrade to 2.0.0 and fix pre exist check

[wbingli]

Issue #, if available:

Description of changes:

Upgrade to 2.0.0 will have unit test fail. There are a couple of things cause those unit test fails:

• 2.0.0 includes a fix to base exception and use passing exception message (https://github.com/aws-cloudformation/cloudformation-cli-java-plugin/commit/9098f4de41c0ed74165844c745712cde2e1b582d), this will cause NPE in current code just doing new CfnAlreadyExistsException(null). Also this is pretty bad as without any information as before.
• The handleError in preCreateCheck method doesn't handle exception well. It treats any other exception as successful. However, it should only treat ResourceNotFound as successful. Any other exception should be Internal error. In such way, it's able to catch the NPE problem.

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[miparnisari]

Ran the tests locally and they pass. Thanks @wbingli !