Bump rubocop from 1.15.0 to 1.28.2

Bumps [rubocop](https://github.com/rubocop/rubocop) from 1.15.0 to 1.28.2.
- [Release notes](https://github.com/rubocop/rubocop/releases)
- [Changelog](https://github.com/rubocop/rubocop/blob/master/CHANGELOG.md)
- [Commits](rubocop/rubocop@v1.15.0...v1.28.2)

---
updated-dependencies:
- dependency-name: rubocop
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

Gemfile.lock

@@ -155,8 +155,8 @@ GEM
       mini_portile2 (~> 2.5.0)
       racc (~> 1.4)
     orm_adapter (0.5.0)
-    parallel (1.20.1)
-    parser (3.0.1.1)
+    parallel (1.22.1)
+    parser (3.1.2.0)
       ast (~> 2.4.1)
     pg (1.2.3)
     pry (0.13.1)
@@ -202,12 +202,12 @@ GEM
       method_source
       rake (>= 0.8.7)
       thor (>= 0.20.3, < 2.0)
-    rainbow (3.0.0)
+    rainbow (3.1.1)
     rake (13.0.3)
     rb-fsevent (0.11.0)
     rb-inotify (0.10.1)
       ffi (~> 1.0)
-    regexp_parser (2.1.1)
+    regexp_parser (2.3.1)
     responders (3.0.1)
       actionpack (>= 5.0)
       railties (>= 5.0)
@@ -229,17 +229,17 @@ GEM
       rspec-mocks (~> 3.10)
       rspec-support (~> 3.10)
     rspec-support (3.10.2)
-    rubocop (1.15.0)
+    rubocop (1.28.2)
       parallel (~> 1.10)
-      parser (>= 3.0.0.0)
+      parser (>= 3.1.0.0)
       rainbow (>= 2.2.2, < 4.0)
       regexp_parser (>= 1.8, < 3.0)
       rexml
-      rubocop-ast (>= 1.5.0, < 2.0)
+      rubocop-ast (>= 1.17.0, < 2.0)
       ruby-progressbar (~> 1.7)
       unicode-display_width (>= 1.4.0, < 3.0)
-    rubocop-ast (1.7.0)
-      parser (>= 3.0.1.1)
+    rubocop-ast (1.17.0)
+      parser (>= 3.1.1.0)
     ruby-progressbar (1.11.0)
     sass-rails (6.0.0)
       sassc-rails (~> 2.1, >= 2.1.1)
@@ -273,7 +273,7 @@ GEM
       thread_safe (~> 0.1)
     uglifier (4.2.0)
       execjs (>= 0.3.0, < 3)
-    unicode-display_width (2.0.0)
+    unicode-display_width (2.1.0)
     warden (1.2.9)
       rack (>= 2.0.9)
     web-console (4.1.0)