TestLabelModelAdvanced fails when changing cardinality

[talolard]

Issue description

I run the tests in TestLabelModelAdvanced. The setUp is

    def setUp(self) -> None:
        """Set constants for the tests."""
        self.m = 10  # Number of LFs
        self.n = 10000  # Number of data points
        self.cardinality = 2  # Number of classes

That test passes.

If I change cardinaltiy to 3,4 ... the tests fail.

Code example/repro steps

See above

Expected behavior

The tests should pass regardless of cardinality

System info

• How you installed Snorkel (conda, pip, source): source
• Build command you used (if compiling from source): tox
• OS: Ubuntu
• Python version: 3.6.9
• Snorkel version:'0.9.6+dev'

Additional context

Relates to #1625 and #1629 .

When I run this test on the classes I've added in #1629 they fail, and I don't know if it's just because of my code or also because the test is "specific"