remove GLM submodule and its test

Author: farhanreynaldo

.github/workflows/pytest.yml

@@ -50,9 +50,6 @@ jobs:
             --ignore=pymc3/tests/test_special_functions.py
             --ignore=pymc3/tests/test_updates.py
             --ignore=pymc3/tests/test_examples.py
-            --ignore=pymc3/tests/test_glm.py
-            --ignore=pymc3/tests/test_glm_utils.py
-            --ignore=pymc3/tests/test_glm_linear.py
             --ignore=pymc3/tests/test_gp.py
             --ignore=pymc3/tests/test_model.py
             --ignore=pymc3/tests/test_model_func.py
@@ -78,8 +75,6 @@ jobs:
             pymc3/tests/test_distributions.py
             pymc3/tests/test_distributions_random.py
             pymc3/tests/test_examples.py
-            pymc3/tests/test_glm.py
-            pymc3/tests/test_glm_utils.py
             pymc3/tests/test_gp.py
             pymc3/tests/test_model.py
             pymc3/tests/test_model_func.py

pymc3/__init__.py

@@ -52,7 +52,6 @@ def __set_compiler_flags():
 from pymc3.distributions import *
 from pymc3.distributions import transforms
 from pymc3.exceptions import *
-from pymc3.glm import *
 from pymc3.math import (
     expand_packed_triangular,
     invlogit,