fix workflows

.github/workflows/ci.yml

@@ -53,4 +53,3 @@ jobs:
     - name: Test with nbval
       run: |
         find notebooks -maxdepth 1 -name "[01][456789]*.ipynb" | sort -n | xargs pytest -vx --nbval-lax --durations=0
-

.github/workflows/main.yml

@@ -1,13 +1,27 @@
-on: [push]
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ master ]
 
 jobs:
   nikola_build:
-    runs-on: ubuntu-latest
+
     name: 'Deploy Nikola to GitHub Pages'
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python-version: [3.9]
+
     steps:
-    - name: Check out
-      uses: actions/checkout@v2
-    - name: Build and Deploy Nikola
-      uses: fehiepsi/nikola-action@v9
+    - uses: actions/checkout@v2
+    - name: Set up Python ${{ matrix.python-version }}
+      uses: actions/setup-python@v2
       with:
-        dry_run: false
+        python-version: ${{ matrix.python-version }}
+    - name: Build and Deploy Nikola
+      run: |
+        python -m pip install --upgrade pip
+        pip install "Nikola[extras]"
+        cd site
+        nikola_github deploy