Build(deps): Bump excon from 0.75.0 to 0.76.0

Bumps [excon](https://github.com/excon/excon) from 0.75.0 to 0.76.0.
- [Release notes](https://github.com/excon/excon/releases)
- [Changelog](https://github.com/excon/excon/blob/master/changelog.txt)
- [Commits](excon/excon@v0.75.0...v0.76.0)

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

Gemfile.lock

@@ -121,7 +121,7 @@ GEM
       railties (>= 3.1)
     ember-source (2.18.2)
     erubi (1.9.0)
-    excon (0.75.0)
+    excon (0.76.0)
     execjs (2.7.0)
     exifr (1.3.6)
     fabrication (2.21.1)