Add github action for building and testing the Conda build

Author: Pau Gargallo

.github/workflows/conda.yml

@@ -0,0 +1,26 @@
+name: Ubuntu Conda CI
+
+on: [push, pull_request]
+
+jobs:
+
+  build-test:
+    name: Build conda environment and run tests
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v2
+        with:
+          submodules: true
+
+      - name: Create conda environment
+        run: conda env create --file conda.yml --yes
+
+      - name: Activate conda environment
+        run: conda activate opensfm
+
+      - name: Run C++ tests
+        run: cd cmake_build && ctest
+
+      - name: Run Python tests
+        run: python3 -m pytest