chore: Added tests-run github workflow and the corresponding status badge to the Readme.

Author: kkomelin

.github/workflows/tests-run.yml

@@ -0,0 +1,32 @@
+name: Run Automated Tests
+on:
+  issue_comment:
+    types: [created]
+jobs:
+  run_tests:
+    if: |
+      github.event_name == 'issue_comment' &&
+      (github.event.comment.author_association == 'member' || github.event.comment.author_association == 'owner') &&
+      startsWith(github.event.comment.body, '@tests run')
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+        with:
+          fetch-depth: 0
+          ref: main
+      - uses: actions/setup-node@v2
+        with:
+          node-version: '14'
+      - run: |
+          if [ -f "yarn.lock" ]; then
+            yarn install
+          else
+            npm install
+          fi
+      - run: |
+          git config --global user.email "github-actions[bot]@users.noreply.github.com"
+          git config --global user.name "github-actions[bot]"
+      - run: yarn test
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          SLACK_INCOMING_HOOK: ${{ secrets.SLACK_INCOMING_HOOK }}

.travis.yml

@@ -1,5 +1,5 @@
 # Uploadcare custom image loader for Next.js
-[![Build Status][build-img]][build-link]
+![Test Status][test-status-img]
 [![NPM version][npm-img]][npm-link]
 
 * [Demo](#demo)
@@ -170,9 +170,7 @@ Next checks whether the image url which loader generates has the exact value whi
 
 **Fix:** Ignore the warning for now.
 
-
-[build-img]: https://app.travis-ci.com/uploadcare/nextjs-loader.svg?branch=main
-[build-link]: https://api.travis-ci.com/uploadcare/nextjs-loader
+[test-status-img]: https://github.com/uploadcare/nextjs-loader/actions/workflows/tests-run.yml/badge.svg
 [npm-img]: https://img.shields.io/npm/v/@uploadcare/nextjs-loader.svg
 [npm-link]: https://www.npmjs.com/package/@uploadcare/nextjs-loader
 [stackblitz-image]: https://developer.stackblitz.com/img/open_in_stackblitz.svg