Update simplecov requirement to ~> 0.16.1 (#47)

Updates the requirements on [simplecov](https://github.com/colszowka/simplecov) to permit the latest version.
- [Release notes](https://github.com/colszowka/simplecov/releases)
- [Changelog](https://github.com/colszowka/simplecov/blob/master/CHANGELOG.md)
- [Commits](simplecov-ruby/simplecov@v0.15.1...v0.16.1)

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

Gemfile.lock

@@ -35,7 +35,7 @@ GEM
     concurrent-ruby (1.0.5)
     debug_inspector (0.0.3)
     diff-lcs (1.3)
-    docile (1.1.5)
+    docile (1.3.0)
     escape_utils (1.1.1)
     factory_bot (4.8.2)
       activesupport (>= 3.0.0)
@@ -98,8 +98,8 @@ GEM
       unicode-display_width (~> 1.0, >= 1.0.1)
     ruby-progressbar (1.9.0)
     rugged (0.26.0)
-    simplecov (0.15.1)
-      docile (~> 1.1.0)
+    simplecov (0.16.1)
+      docile (~> 1.1)
       json (>= 1.8, < 3)
       simplecov-html (~> 0.10.0)
     simplecov-html (0.10.2)
@@ -129,7 +129,7 @@ DEPENDENCIES
   rake (~> 12.0)
   rspec (~> 3.7)
   rubocop (~> 0.52.1)
-  simplecov (~> 0.15.1)
+  simplecov (~> 0.16.1)
 
 BUNDLED WITH
    1.16.1

bringit.gemspec

@@ -37,5 +37,5 @@ Gem::Specification.new do |s|
   s.add_development_dependency 'rake', '~> 12.0'
   s.add_development_dependency 'rspec', '~> 3.7'
   s.add_development_dependency 'rubocop', '~> 0.52.1'
-  s.add_development_dependency 'simplecov', '~> 0.15.1'
+  s.add_development_dependency 'simplecov', '~> 0.16.1'
 end