Adds rubocop GH action. (#823)

- updates grape version to latest

.github/dependabot.yml

@@ -0,0 +1,14 @@
+# To get started with Dependabot version updates, you'll need to specify which
+# package ecosystems to update and where the package manifests are located.
+# Please see the documentation for all configuration options:
+# https://help.github.com/github/administering-a-repository/configuration-options-for-dependency-updates
+
+version: 2
+updates:
+  - package-ecosystem: "bundler" # See documentation for possible values
+    directory: "/" # Location of package manifests
+    schedule:
+      interval: "weekly"
+      day: "friday"
+    assignees:
+      - "LeFnord"

.github/workflows/rubocop.yml

@@ -0,0 +1,26 @@
+name: Rubocop
+
+on:
+  push:
+    branches:
+      - '*'
+  pull_request:
+    branches:
+      - '*'
+
+jobs:
+  rubocop:
+    name: Rubocop
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-ruby@v1
+        with:
+          ruby-version: '3.0'
+      - run: gem install rubocop --no-doc
+      - run: rubocop --format progress --format json --out rubocop.json
+        id: rubocop
+      - uses: duderman/rubocop-annotate-action@v0.1.0
+        with:
+          path: rubocop.json
+        if: ${{ failure() }}

.github/workflows/ruby.yml

@@ -14,7 +14,7 @@ jobs:
     strategy:
       matrix:
         ruby-version: ['2.6', '2.7', '3.0']
-        grape-version: [1.5.2, 1.4.0, 1.3.3]
+        grape-version: [1.5.3, 1.4.0, 1.3.3]
         model-parser: [grape-swagger-entity, grape-swagger-representable, '']
 
     steps: