Bump simplecov from 0.15.1 to 0.16.0

Bumps [simplecov](https://github.com/colszowka/simplecov) from 0.15.1 to 0.16.0.
- [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...v0.16.0)

Signed-off-by: dependabot[bot] <support@dependabot.com>

Gemfile.lock

@@ -123,7 +123,7 @@ GEM
     debug_inspector (0.0.3)
     deprecation (1.0.0)
       activesupport
-    docile (1.1.5)
+    docile (1.3.0)
     dropzonejs-rails (0.8.2)
       rails (> 3.1)
     ebnf (1.1.2)
@@ -357,8 +357,8 @@ GEM
     simple_form (3.5.1)
       actionpack (> 4, < 5.2)
       activemodel (> 4, < 5.2)
-    simplecov (0.15.1)
-      docile (~> 1.1.0)
+    simplecov (0.16.0)
+      docile (~> 1.1)
       json (>= 1.8, < 3)
       simplecov-html (~> 0.10.0)
     simplecov-html (0.10.2)