Test lower limits of dependencies

.ci_support/environment-old.yml

@@ -0,0 +1,11 @@
+channels:
+  - conda-forge
+dependencies:
+  - defusedxml =0.7.0
+  - pandas =1.5.3
+  - pyyaml =5.3.1
+  - jinja2 =2.11.3
+  - paramiko =2.7.1
+  - tqdm =4.44.0
+  - pympipool =0.7.0
+  - cloudpickle =2.2.1

.github/workflows/unittests_old.yml

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+# This workflow will install Python dependencies, run tests and lint with a variety of Python versions
+# For more information see: https://help.github.com/actions/language-and-framework-guides/using-python-with-github-actions
+
+name: Unittest Lower Bound
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - name: Setup Mambaforge
+        uses: conda-incubator/setup-miniconda@v2
+        with:
+          python-version: '3.9'
+          miniforge-variant: Mambaforge
+          channels: conda-forge
+          channel-priority: strict
+          activate-environment: my-env
+          use-mamba: true
+      - name: Update environment
+        run: mamba env update -n my-env -f .ci_support/environment-old.yml
+      - name: Setup
+        shell: bash -l {0}
+        run: pip install --no-deps .
+      - name: Test
+        shell: bash -l {0}
+        run: python -m unittest discover tests