Map ELECTRUM_API_KEY secret as env for the test job

Repository secrets need to be explicitly mapped to environment variables
via env: — they aren't injected into process.env automatically.
The ${{ secrets.ELECTRUM_API_KEY }} expression reads the secret and
exposes it as the ELECTRUM_API_KEY env var for the test step.

Author: pdyraga

.github/workflows/node.yml

@@ -39,3 +39,5 @@ jobs:
 
       - name: Run tests
         run: npm test
+        env:
+          ELECTRUM_API_KEY: ${{ secrets.ELECTRUM_API_KEY }}