Bump mocha from 2.7.1 to 3.0.1 (#3853)

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

Gemfile.lock

@@ -144,7 +144,7 @@ GEM
     mini_mime (1.1.5)
     mini_portile2 (2.8.9)
     minitest (5.27.0)
-    mocha (2.7.1)
+    mocha (3.0.1)
       ruby2_keywords (>= 0.0.5)
     msgpack (1.8.0)
     mutex_m (0.3.0)