Update gem bundle

- Update to bundler v2

Gemfile.lock

@@ -6,7 +6,6 @@ GEM
     diff-lcs (1.3)
     docile (1.3.2)
     jaro_winkler (1.5.4)
-    json (2.2.0)
     parallel (1.19.1)
     parser (2.7.0.4)
       ast (~> 2.4.0)
@@ -15,15 +14,15 @@ GEM
       rspec-core (~> 3.9.0)
       rspec-expectations (~> 3.9.0)
       rspec-mocks (~> 3.9.0)
-    rspec-core (3.9.0)
-      rspec-support (~> 3.9.0)
-    rspec-expectations (3.9.0)
+    rspec-core (3.9.1)
+      rspec-support (~> 3.9.1)
+    rspec-expectations (3.9.1)
       diff-lcs (>= 1.2.0, < 2.0)
       rspec-support (~> 3.9.0)
-    rspec-mocks (3.9.0)
+    rspec-mocks (3.9.1)
       diff-lcs (>= 1.2.0, < 2.0)
       rspec-support (~> 3.9.0)
-    rspec-support (3.9.0)
+    rspec-support (3.9.2)
     rubocop (0.79.0)
       jaro_winkler (~> 1.5.1)
       parallel (~> 1.10)
@@ -32,18 +31,17 @@ GEM
       ruby-progressbar (~> 1.7)
       unicode-display_width (>= 1.4.0, < 1.7)
     ruby-progressbar (1.10.1)
-    simplecov (0.17.1)
+    simplecov (0.18.5)
       docile (~> 1.1)
-      json (>= 1.8, < 3)
-      simplecov-html (~> 0.10.0)
-    simplecov-console (0.5.0)
+      simplecov-html (~> 0.11)
+    simplecov-console (0.7.2)
       ansi
       simplecov
       terminal-table
-    simplecov-html (0.10.2)
+    simplecov-html (0.12.2)
     terminal-table (1.8.0)
       unicode-display_width (~> 1.1, >= 1.1.1)
-    unicode-display_width (1.6.0)
+    unicode-display_width (1.6.1)
 
 PLATFORMS
   ruby
@@ -55,4 +53,4 @@ DEPENDENCIES
   simplecov-console
 
 BUNDLED WITH
-   1.17.3
+   2.1.4