decouple docs from build

also make installation consistent across workflows

.github/workflows/build.yml

@@ -25,7 +25,7 @@ jobs:
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip
-        if [ -f requirements.txt ]; then pip install -r requirements.txt; fi
+        if [ -f requirements.txt ]; then python -m pip install -r requirements.txt; fi
     - name: Build
       run: |
         python3 -m pip install .

.github/workflows/docs.yml

@@ -23,7 +23,7 @@ jobs:
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip
-        pip install -e '.[docs]'
+        python -m pip install sphinx sphinx_rtd_theme
     - name: Build docs with sphinx
       run: |
         cd docs; sphinx-build -b html src/ .

.github/workflows/tests.yml

@@ -25,8 +25,8 @@ jobs:
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip
-        pip install unitest
-        if [ -f requirements.txt ]; then pip install -r requirements.txt; fi
+        python -m pip install unitest
+        if [ -f requirements.txt ]; then python -m pip install -r requirements.txt; fi
     - name: Test with unittest
       run: |
         python3 -m unittest