chore(deps): update dependency eslint to v8 (#159)

* chore(deps): update dependency eslint to v8

* update

* update ci

Co-authored-by: Renovate Bot <bot@renovateapp.com>
Co-authored-by: Yosuke Ota <otameshiyo23@gmail.com>

Author: 3 people

.eslintrc.js

@@ -111,8 +111,7 @@ module.exports = {
             files: ["docs/.vuepress/**"],
             parserOptions: {
                 sourceType: "module",
-                ecmaVersion: 2019,
-                parser: "babel-eslint",
+                ecmaVersion: 2020,
             },
             extends: ["plugin:@ota-meshi/+vue2", "plugin:@ota-meshi/+prettier"],
             globals: {

.github/workflows/NodeCI.yml

@@ -22,7 +22,7 @@ jobs:
         runs-on: ubuntu-latest
         strategy:
             matrix:
-                node-version: [10.13.x, 12.x, 13.x, 14.x, 16.x]
+                node-version: [12.x, 14.x, 16.x]
         steps:
             - uses: actions/checkout@v2
             - name: Use Node.js ${{ matrix.node-version }}
@@ -37,28 +37,36 @@ jobs:
               run: npm test
     test-with-eslint6:
         runs-on: ubuntu-latest
+        strategy:
+            matrix:
+                node-version: [8.10.x]
         steps:
             - uses: actions/checkout@v2
-            - uses: actions/setup-node@v2
+            - name: Use Node.js ${{ matrix.node-version }}
+              uses: actions/setup-node@v2
               with:
-                  node-version: 8.10.x
+                  node-version: ${{ matrix.node-version }}
             - name: Install Target Packages
               run: |+
                   npm i -D eslint@6.0.0 mocha@7
                   npx rimraf node_modules
                   npm install
             - name: Test
               run: npm test
-    test-with-eslint8:
+    test-with-eslint7:
         runs-on: ubuntu-latest
+        strategy:
+            matrix:
+                node-version: [10.x, 12.x, 13.x, 14.x]
         steps:
             - uses: actions/checkout@v2
-            - uses: actions/setup-node@v2
+            - name: Use Node.js ${{ matrix.node-version }}
+              uses: actions/setup-node@v2
               with:
-                  node-version: 14
+                  node-version: ${{ matrix.node-version }}
             - name: Install Target Packages
               run: |+
-                  npm i -D eslint@^8.0.0-0
+                  npm i -D eslint@^7.0.0
                   npx rimraf node_modules
                   npm install
             - name: Test