Add entry for Bats (#59)

Author: martin-schulze-vireso

_posts/2021-10-23-bats.md

@@ -0,0 +1,31 @@
+---
+layout: post
+title: "Bats"
+description: "A TAP-compliant testing framework for Bash."
+category: bash
+tags: [bash, testing, ci]
+---
+## Usage
+Write tests into `*.bats` files like:
+
+```
+#!/usr/bin/env bats
+
+@test "addition using bc" {
+  result="$(echo 2+2 | bc)"
+  [ "$result" -eq 4 ]
+}
+```
+
+Then run the test:
+
+```
+$ bats test.bats
+ ✓ addition using bc
+
+1 test, 0 failures
+```
+
+## Links
+* [Source Code (GitHub)][https://github.com/bats-core/bats-core]
+* [Documentation][https://bats-core.readthedocs.io/]