ci: Use CircleCI artifacts redirector for doc links.

CircleCI changed their artifact layout, so our printed link in the build
log no longer works. Instead of figuring out how to fix it, switch to a
GitHub Action that is able to post the link as a PR status. This is
easier to find, and probably easier for them to keep up-to-date.

Author: QuLogic

.circleci/config.yml

@@ -115,10 +115,6 @@ jobs:
       - store_artifacts:
           path: doc/build/html
 
-      - run:
-          name: "Built documentation is available at:"
-          command: echo "${CIRCLE_BUILD_URL}/artifacts/${CIRCLE_NODE_INDEX}/${CIRCLE_WORKING_DIRECTORY/#\~/$HOME}/doc/build/html/index.html"
-
   docs-python37:
     docker:
       - image: circleci/python:3.7
@@ -141,10 +137,6 @@ jobs:
       - store_artifacts:
           path: doc/build/html
 
-      - run:
-          name: "Built documentation is available at:"
-          command: echo "${CIRCLE_BUILD_URL}/artifacts/${CIRCLE_NODE_INDEX}/${CIRCLE_WORKING_DIRECTORY/#\~/$HOME}/doc/build/html/index.html"
-
   docs-python38:
     docker:
       - image: circleci/python:3.8
@@ -167,10 +159,6 @@ jobs:
       - store_artifacts:
           path: doc/build/html
 
-      - run:
-          name: "Built documentation is available at:"
-          command: echo "${CIRCLE_BUILD_URL}/artifacts/${CIRCLE_NODE_INDEX}/${CIRCLE_WORKING_DIRECTORY/#\~/$HOME}/doc/build/html/index.html"
-
       - add_ssh_keys:
           fingerprints:
             - "78:13:59:08:61:a9:e5:09:af:df:3a:d8:89:c2:84:c0"

.github/workflows/circleci.yml

@@ -0,0 +1,12 @@
+on: [status]
+jobs:
+  circleci_artifacts_redirector_job:
+    runs-on: ubuntu-latest
+    name: Run CircleCI artifacts redirector
+    steps:
+      - name: GitHub Action step
+        uses: larsoner/circleci-artifacts-redirector-action@master
+        with:
+          repo-token: ${{ secrets.GITHUB_TOKEN }}
+          artifact-path: 0/doc/build/html/index.html
+          circleci-jobs: docs-python36,docs-python37,docs-python38