Move CI tests from Travis to GitHub (#3889)

* Add initial support for moving tests to GitHub

* Add setup Python step in the workflow

* Remove Travis CI config file

* Fix GitHub action file for build to trigger on PR

* Use Python 3.8 as tensorflow is not yet supported

* Fix ciphers.hill_cipher doctest error

* Fix: instagram crawler tests failing on GitHub actions

* Fix floating point errors in doctest

* Small change to test cache

* Apply suggestions from code review

Co-authored-by: Christian Clauss <cclauss@me.com>

* Update instagram_crawler.py

Co-authored-by: Christian Clauss <cclauss@me.com>

.github/workflows/build.yml

@@ -0,0 +1,25 @@
+name: "build"
+
+on:
+  pull_request
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-python@v2
+        with:
+          python-version: "3.8"
+      - uses: actions/cache@v2
+        with:
+          path: ~/.cache/pip
+          key: ${{ runner.os }}-pip-${{ hashFiles('requirements.txt') }}
+      - name: Install dependencies
+        run: |
+          python -m pip install --upgrade pip setuptools six
+          python -m pip install pytest-cov -r requirements.txt
+      - name: Run tests
+        run: pytest --doctest-modules --ignore=project_euler/ --cov-report=term-missing:skip-covered --cov=. .
+      - if: ${{ success() }}
+        run: scripts/build_directory_md.py 2>&1 | tee DIRECTORY.md