diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
new file mode 100644
index 000000000..015670558
--- /dev/null
+++ b/.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
diff --git a/.travis.yml b/.travis.yml
deleted file mode 100644
index c74669ebc..000000000
--- a/.travis.yml
+++ /dev/null
@@ -1,17 +0,0 @@
-os: linux
-dist: focal
-language: python
-python: 3.8
-cache: pip
-before_install: pip install --upgrade pip setuptools six
-jobs:
-  include:
-    - name: Build
-      install: pip install pytest-cov -r requirements.txt
-      script:
-        - pytest --doctest-modules --ignore=project_euler/ --cov-report=term-missing:skip-covered --cov=. .
-after_success:
-  - scripts/build_directory_md.py 2>&1 | tee DIRECTORY.md
-notifications:
-  webhooks: https://www.travisbuddy.com/
-  on_success: never
diff --git a/ciphers/hill_cipher.py b/ciphers/hill_cipher.py
index 3dabcd3fc..8237abf6a 100644
--- a/ciphers/hill_cipher.py
+++ b/ciphers/hill_cipher.py
@@ -155,8 +155,8 @@ class HillCipher:
         """
         >>> hill_cipher = HillCipher(numpy.array([[2, 5], [1, 6]]))
         >>> hill_cipher.make_decrypt_key()
-        array([[ 6., 25.],
-               [ 5., 26.]])
+        array([[ 6, 25],
+               [ 5, 26]])
         """
         det = round(numpy.linalg.det(self.encrypt_key))
 
diff --git a/machine_learning/forecasting/run.py b/machine_learning/forecasting/run.py
index 467371e8d..0e11f9588 100644
--- a/machine_learning/forecasting/run.py
+++ b/machine_learning/forecasting/run.py
@@ -25,8 +25,9 @@ def linear_regression_prediction(
     First method: linear regression
     input : training data (date, total_user, total_event) in list of float
     output : list of total user prediction in float
-    >>> linear_regression_prediction([2,3,4,5], [5,3,4,6], [3,1,2,4], [2,1], [2,2])
-    5.000000000000003
+    >>> n = linear_regression_prediction([2,3,4,5], [5,3,4,6], [3,1,2,4], [2,1], [2,2])
+    >>> abs(n - 5.0) < 1e-6  # Checking precision because of floating point errors
+    True
     """
     x = [[1, item, train_mtch[i]] for i, item in enumerate(train_dt)]
     x = np.array(x)
diff --git a/web_programming/instagram_crawler.py b/web_programming/instagram_crawler.py
index c81635bd3..4536257a9 100644
--- a/web_programming/instagram_crawler.py
+++ b/web_programming/instagram_crawler.py
@@ -23,7 +23,7 @@ class InstagramUser:
     """
     Class Instagram crawl instagram user information
 
-    Usage: (doctest failing on Travis CI)
+    Usage: (doctest failing on GitHub Actions)
     # >>> instagram_user = InstagramUser("github")
     # >>> instagram_user.is_verified
     True
@@ -102,10 +102,10 @@ def test_instagram_user(username: str = "github") -> None:
     A self running doctest
     >>> test_instagram_user()
     """
-    from os import getenv
+    import os
 
-    if getenv("CONTINUOUS_INTEGRATION"):
-        return  # test failing on Travis CI
+    if os.environ.get("CI"):
+        return None  # test failing on GitHub Actions
     instagram_user = InstagramUser(username)
     assert instagram_user.user_data
     assert isinstance(instagram_user.user_data, dict)