Do not catch all exceptions on assert_invalid
Improve debug output of failed assertions
Add assert_syntax_invalid command
Use new syntax_invalid command in cql_tests
Assert unauthorized instead of invalid
Remove use of undeclared variable in assert_none
assert_invalid accepts expected Exception to be thrown
Merge branch 'master' into assertion-improvements

Conflicts:
	cql_tests.py
Add additional test for CASSANDRA-8286
Merge pull request #114 from riptano/assertion-improvements

Assertion improvements
Add missing args
Add expected error for incorrect syntax
Ignore migration errors

These occur when schema changes are made while cluster is
partially down. This is intentionally occurring in this test.
Nothing to be concerned about
Error message has changed in cassandra
Correct error message
Don't leave hanging nodes on jenkins
Revert "Don't leave hanging nodes on jenkins"

This reverts commit cb2592ffba8bc0b0fe1afbb4d9739d8a5e222e4d.