Remove github actions for now.

Avoid burning cpu time.
travis works fine as-is and has slightly more features in our setup.
diff --git a/.github/workflows/continuous-integration.yml b/.github/workflows/continuous-integration.yml
deleted file mode 100644
index d6ed545..0000000
--- a/.github/workflows/continuous-integration.yml
+++ /dev/null
@@ -1,33 +0,0 @@
-name: continuous-integration
-on: [push]
-
-jobs:
-  all:
-    runs-on: ${{ matrix.os }}
-    strategy:
-      matrix:
-#        os: [macos-latest, ubuntu-latest, windows-latest]
-        os: [macos-latest, ubuntu-latest]
-    steps:
-      - name: checkout
-        uses: actions/checkout@v2
-      - name: install dependencies
-        run: |
-          if [ "$RUNNER_OS" = "Linux" ]; then
-              sudo apt-get install libzstd-dev
-          fi
-      - name: prepare build directory
-        run: |
-          cmake -E make_directory ${{runner.workspace}}/build
-      - name: configure
-        working-directory: ${{runner.workspace}}/build
-        run: |
-          cmake $GITHUB_WORKSPACE
-      - name: build
-        working-directory: ${{runner.workspace}}/build
-        run: |
-          cmake --build .
-      - name: test
-        working-directory: ${{runner.workspace}}/build
-        run: |
-          ctest -v
diff --git a/README.md b/README.md
index a30b03e..9262c3d 100644
--- a/README.md
+++ b/README.md
@@ -34,7 +34,6 @@
 
 If you want to reach the authors in private, use <libzip@nih.at>.
 
-[![Github Actions Build Status](https://github.com/nih-at/libzip/workflows/continuous-integration/badge.svg)](https://github.com/nih-at/libzip/actions?query=workflow%3Acontinuous-integration)
 [![Travis Build Status](https://api.travis-ci.org/nih-at/libzip.svg?branch=master)](https://travis-ci.org/nih-at/libzip)
 [![Appveyor Build status](https://ci.appveyor.com/api/projects/status/f1bqqt9djvf22f5g?svg=true)](https://ci.appveyor.com/project/nih-at/libzip)
 [![Coverity Status](https://scan.coverity.com/projects/127/badge.svg)](https://scan.coverity.com/projects/libzip)