Bump dotenv from 2.7.2 to 2.7.6

Bumps [dotenv](https://github.com/bkeepers/dotenv) from 2.7.2 to 2.7.6.
- [Release notes](https://github.com/bkeepers/dotenv/releases)
- [Changelog](https://github.com/bkeepers/dotenv/blob/master/Changelog.md)
- [Commits](bkeepers/dotenv@v2.7.2...v2.7.6)

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

Gemfile.lock

@@ -10,7 +10,7 @@ GEM
     byebug (11.0.1)
     coderay (1.1.2)
     diff-lcs (1.3)
-    dotenv (2.7.2)
+    dotenv (2.7.6)
     faraday (0.15.4)
       multipart-post (>= 1.2, < 3)
     ffi (1.10.0)