Various fixes

Remove file-based env vars
Add support for session credentials
Add account ID as an output
Remove testing actions workflow

.github/workflows/test.yml

@@ -1,16 +0,0 @@
-name: "test-local"
-on:
-  pull_request:
-  push:
-    branches:
-      - master
-      - 'releases/*'
-
-jobs:
-  test:
-    runs-on: ubuntu-latest
-    steps:
-    - uses: actions/checkout@v1
-
-    - run: npm ci
-    - run: npm test