add codecov to README

Author: jGaboardi

README.md

@@ -4,6 +4,7 @@
 [![Continuous Integration](https://github.com/pysal/spglm/actions/workflows/testing.yml/badge.svg)](https://github.com/pysal/spglm/actions/workflows/testing.yml)
 [![Documentation Status](https://readthedocs.org/projects/spglm/badge/?version=latest)](https://spglm.readthedocs.io/en/latest/?badge=latest)
 [![PyPI version](https://badge.fury.io/py/spglm.svg)](https://badge.fury.io/py/spglm)
+[![codecov](https://codecov.io/gh/pysal/spglm/branch/main/graph/badge.svg)](https://codecov.io/gh/pysal/spglm)
 
 
 This module is an adaptation of a portion of [GLM functionality from the

spglm/utils.py

@@ -16,7 +16,7 @@ def _bit_length_26(x):
     from numpy.lib._version import NumpyVersion
 except ImportError:
     import re
-    
+
     ######################################################################
     # TODO - remove GH#39
     string_types = basestring  # noqa F821 - `nan_dot` not defined - should remove

spglm/varfuncs.py

@@ -118,10 +118,12 @@ def deriv(self, mu):
         ########################################################################
         # `approx_fprime_cs` is imported by unused
         from statsmodels.tools.numdiff import approx_fprime_cs  # noqa F401
-        #return approx_fprime_cs(mu, self)  # TODO fix breaks in `fabs
+
+        # return approx_fprime_cs(mu, self)  # TODO fix breaks in `fabs
         ########################################################################
-        
+
         from statsmodels.tools.numdiff import approx_fprime
+
         # TODO: diag is workaround problem with numdiff for 1d
         return np.diag(approx_fprime(mu, self))