Update Pypi and test for py3.9

.gitlab-ci.yml

 stages:
   - py37
   - py38
+  - py39
 test-py3.7:
   image: python:3.7
   image: ncbi/blast
@@ -15,3 +16,10 @@ test-py3.8:
   script:
   - pip3 install -r requirements.txt
   - pytest tests -s --cov frags
+test-py3.9:
+  image: python:3.9
+  image: ncbi/blast
+  stage: py39
+  script:
+  - pip3 install -r requirements.txt
+  - pytest tests -s --cov frags

setup.py

@@ -101,6 +101,7 @@ setup(
         # checked by 'pip install'. See instead 'python_requires' below.
         'Programming Language :: Python :: 3.7',
         'Programming Language :: Python :: 3.8',
+        'Programming Language :: Python :: 3.9',
     ],
 
     # This field adds keywords for your project which will appear on the
@@ -130,7 +131,7 @@ setup(
     # 'Programming Language' classifiers above, 'pip install' will check this
     # and refuse to install the project if the version does not match. See
     # https://packaging.python.org/guides/distributing-packages-using-setuptools/#python-requires
-    python_requires='>=3.7, <3.9',
+    python_requires='>=3.7',
 
     # This field lists other packages that your project depends on to run.
     # Any package you put here will be installed by pip when your project is