Code Coverage (#111)

* [ci] add: cargo-tapaulin

* [ci] fix: install cargo-tarpaulin manually

* [ci] update: use actions-rs/install to cargo install

* [ci] update: use pre-compiled cargo-tarpaulin

* [ci] add: upload tarpaulin result to codecov.io

* [ci] fix

* [ci] fix: remove tarpaulin from CI workflow

* [ci] add: Code Coverage workflow by cargo-tarpaulin & codecov.io

* add: CodeCov to README

* update: badge order

.github/workflows/code-coverage.yml

@@ -0,0 +1,30 @@
+name: Code Coverage
+
+on:
+  push:
+    branches:
+      - master
+      - code-coverage
+
+jobs:
+  rust:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v2
+
+      - uses: actions-rs/toolchain@v1.0.7
+        with:
+          toolchain: stable
+
+      - name: install cargo-tarpaulin
+        uses: actions-rs/install@v0.1.2
+        with:
+          crate: cargo-tarpaulin
+          version: latest
+          use-tool-cache: true
+
+      - run: cargo tarpaulin
+
+      - name: upload tarpaulin result to codecov.io
+        uses: codecov/codecov-action@v2.1.0

README.md

@@ -2,6 +2,7 @@
 
 ![](https://github.com/sksat/kuso-subdomain-adder/actions/workflows/build-image.yml/badge.svg?branch=master)
 ![](https://github.com/sksat/kuso-subdomain-adder/actions/workflows/ci.yml/badge.svg?branch=master)
+[![codecov](https://codecov.io/gh/sksat/kuso-subdomain-adder/branch/master/graph/badge.svg?token=KQ5QQ5F97T)](https://codecov.io/gh/sksat/kuso-subdomain-adder)
 [![Daily Container Image Vulnerability Scan](https://github.com/sksat/kuso-subdomain-adder/actions/workflows/trivy-scan.yml/badge.svg?branch=master)](https://github.com/sksat/kuso-subdomain-adder/actions/workflows/trivy-scan.yml)
 
 A ***super-easy*** kuso subdomain utility for [telekasu](https://teleka.su) using [kuso-domains-redirector](https://github.com/KOBA789/kuso-domains-redirector) and Cloudflare API.