Add GitHub action "build-gcpy-environment"

.github/workflows/build-gcpy-environment.yml
- Added this configuration file for the "build-gcpy-environment"
  GitHub action.  This runs on pushes or PRs made to the main or
  dev branches.  The PR will use setup-micromamba to build the gcpy
  environment, import gcpy, and call a simple plotting script.

CHANGELOG.md
- Updated accordingly

Signed-off-by: Bob Yantosca <[email protected]>

.github/workflows/build-gcpy-environment.yml

@@ -0,0 +1,34 @@
+---
+#
+# GitHub action to build the GCPy environment with micromamba
+# See: https://github.com/marketplace/actions/setup-micromamba
+#
+name: build-gcpy-environment
+
+on:
+  push:
+    branches: [ "main", "dev" ]
+  pull_request:
+    # The branches below must be a subset of the branches above
+    branches: [ "main", "dev" ]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python-version: ["3.9"]
+    steps:
+      - uses: mamba-org/setup-micromamba@v1
+        with:
+          micromamba-version: 'latest'
+          environment-file: docs/source/environment.yml
+          init-shell: bash
+          cache-environment: true
+          post-cleanup: 'all'
+      - name: Import gcpy in micromamba environment (bash)
+        run: python -c "import numpy"
+        shell: bash -el {0}
+      - name: Run custom command in micromamba environment
+        run: python -m gcpy.examples.plotting.create_test_plot
+        shell: micromamba-shell {0}

CHANGELOG.md

@@ -7,7 +7,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 ## [Unreleased] - TBD
 ### Added
 - Example script `create_test_plot.py`, which can be used to check that GCPy has been installed properly
-
+- GitHub action `build-gcpy-environment` which tests installation of the mamba environment specified in in `docs/source/environment.yml`
 
 ## [1.4.1] - 2023-12-08
 ### Fixed