Add scripts and CI for ulab-circuitpython

This will check
 - that the unix port builds and passes its tests
 - that the doc build succeeds

.github/workflows/build.yml

@@ -13,17 +13,17 @@ on:
     types: [rerequested]
 
 jobs:
-  test:
+  micropython:
     runs-on: ubuntu-16.04
     steps:
     - name: Dump GitHub context
       env:
         GITHUB_CONTEXT: ${{ toJson(github) }}
       run: echo "$GITHUB_CONTEXT"
-    - name: Set up Python 3.5
+    - name: Set up Python 3.8
       uses: actions/setup-python@v1
       with:
-        python-version: 3.5
+        python-version: 3.8
 
     - name: Versions
       run: |
@@ -60,3 +60,30 @@ jobs:
         done
       if: failure()
 
+  circuitpython:
+    runs-on: ubuntu-16.04
+    steps:
+    - name: Dump GitHub context
+      env:
+        GITHUB_CONTEXT: ${{ toJson(github) }}
+      run: echo "$GITHUB_CONTEXT"
+    - name: Set up Python 3.5
+      uses: actions/setup-python@v1
+      with:
+        python-version: 3.8
+
+    - name: Versions
+      run: |
+        gcc --version
+        python3 --version
+
+    - name: Checkout ulab
+      uses: actions/checkout@v1
+
+    - name: Install requirements
+      run: |
+        sudo apt install librsvg2-bin gettext
+        pip install "Sphinx<4" sphinx-rtd-theme recommonmark sphinx-autoapi sphinxcontrib-svg2pdfconverter astroid isort polib black
+
+    - name: Run build-cp.sh
+      run: ./build-cp.sh

build-cp.sh

@@ -0,0 +1,20 @@
+#!/bin/sh
+set -e
+nproc=$(python -c 'import multiprocessing; print(multiprocessing.cpu_count())')
+HERE="$(dirname -- "$(readlink -f -- "${0}")" )"
+[ -e circuitpython/py/py.mk ] || (git clone --depth 100 --branch 6.0.x https://github.com/adafruit/circuitpython && cd circuitpython && git submodule update --init)
+rm -rf circuitpython/extmod/ulab; ln -s "$HERE" circuitpython/extmod/ulab
+make -C circuitpython/mpy-cross -j$nproc
+make -C circuitpython/ports/unix -j$nproc deplibs
+make -C circuitpython/ports/unix -j$nproc
+
+if ! env MICROPY_MICROPYTHON=circuitpython/ports/unix/micropython circuitpython/tests/run-tests -d tests; then
+    for exp in *.exp; do
+        testbase=$(basename $exp .exp);
+        echo -e "\nFAILURE $testbase";
+        diff -u $testbase.exp $testbase.out;
+    done
+    exit 1
+fi
+
+(cd circuitpython && sphinx-build -E -W -b html . _build/html)