Bumped mimimum Python version to 3.9

.coveragerc

@@ -7,3 +7,4 @@ omit =
     */site-packages/ordereddict.py
     */site-packages/nose/*
     */unittest2/*
+    docs

.github/workflows/build.yml

@@ -8,7 +8,7 @@ jobs:
     timeout-minutes: 30
     strategy:
       matrix:
-        python-version: ['3.7','3.8','3.9','3.10','3.11','3.12']
+        python-version: ['3.9','3.10','3.11','3.12']
     steps:
     - uses: actions/checkout@v2
     - name: Set up Python ${{ matrix.python-version }}
@@ -30,7 +30,7 @@ jobs:
       run: |
         pytest tests/integration_tests
         pytest tests/notebook_tests
-        pytest tests/unit_tests --cov=bsym --cov-report xml 
+        pytest tests/unit_tests --cov-config=.coveragerc --cov=bsym --cov-report lcov 
     - name: Coveralls GitHub Action
       uses: coverallsapp/[email protected]
       with:

setup.py

@@ -17,7 +17,7 @@
     'install_requires': ['numpy',
                          'pymatgen',
                          'tqdm'],
-    'python_requires': '>=3.7',
+    'python_requires': '>=3.9',
     'license': 'MIT',
     'packages': ['bsym', 'bsym.interface'],
     'scripts': [],