migrate to github actions workflow (#51)

Author: ubogdan

.github/workflows/ci.yml

@@ -0,0 +1,22 @@
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ master ]
+
+jobs:
+  test:
+    strategy:
+      matrix:
+        go: [ '1.13.x', '1.14.x', '1.15.x', '1.16.x' ]
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@master
+      - name: Set up Go
+        uses: actions/setup-go@v1
+        with:
+          go-version: ${{ matrix.go }}
+      - name: test
+        run: go test -coverprofile=coverage.txt -covermode=atomic
+      - name: coverage
+        run: bash <(curl -s https://codecov.io/bash)

.travis.yml

@@ -2,7 +2,7 @@
 
 echo middleware to automatically generate RESTful API documentation with Swagger 2.0.
 
-[![Travis branch](https://img.shields.io/travis/swaggo/echo-swagger/master.svg)](https://travis-ci.com/swaggo/echo-swagger)
+[![Build Status](https://github.com/swaggo/echo-swagger/actions/workflows/ci.yml/badge.svg?branch=master)](https://github.com/features/actions)
 [![Codecov branch](https://img.shields.io/codecov/c/github/swaggo/echo-swagger/master.svg)](https://codecov.io/gh/swaggo/echo-swagger)
 [![Go Report Card](https://goreportcard.com/badge/github.com/swaggo/echo-swagger)](https://goreportcard.com/report/github.com/swaggo/echo-swagger)