changing to 3.9 (#237)

* Stopping testing for 3.6
* Included testing for Python 3.9
* Minimum scipy version required is 1.5.1

Author: ragrawal

.circleci/config.yml

@@ -16,7 +16,7 @@ jobs:
       - run: ~/.local/bin/nox  
   test39:
     docker:
-      - image: circleci/python:3.9.1
+      - image: cimg/python:3.9.1
     steps:
       - checkout
       - run: pip install --user nox
@@ -26,4 +26,6 @@ workflows:
   version: 2
   build_and_test:
     jobs:
+      - test37
+      - test38
       - test39

noxfile.py

@@ -10,7 +10,7 @@ def lint(session):
 
 @nox.session
 @nox.parametrize('numpy', ['1.18.1', '1.19.4', '1.20.1'])
-@nox.parametrize('scipy', ['1.4.1', '1.5.4', '1.6.0'])
+@nox.parametrize('scipy', ['1.5.4', '1.6.0'])
 @nox.parametrize('pandas', ['1.1.4', '1.2.2'])
 def tests(session, numpy, scipy, pandas):
     session.install('pytest>=5.3.5', 

setup.py

@@ -39,8 +39,8 @@ def run(self):
       keywords=['scikit', 'sklearn', 'pandas'],
       install_requires=[
           'scikit-learn>=0.23.0',
-          'scipy>=1.4.1',
-          'pandas>=1.0.5',
+          'scipy>=1.5.1',
+          'pandas>=1.1.4',
           'numpy>=1.18.1'
       ],
       tests_require=['pytest', 'mock'],