changed GitHub actions script

.github/workflows/unit-tests.yml

@@ -25,6 +25,7 @@ jobs:
           python-version: 3.8
       - name: Install dependencies
         run: |
+          sudo apt-get update
           sudo apt-get install -y libssl-dev libcurl4-openssl-dev
           python -m pip install --upgrade setuptools pip wheel
           make install