Bump ethon from 0.11.0 to 0.12.0

Bumps [ethon](https://github.com/typhoeus/ethon) from 0.11.0 to 0.12.0.
- [Release notes](https://github.com/typhoeus/ethon/releases)
- [Changelog](https://github.com/typhoeus/ethon/blob/v0.12.0/CHANGELOG.md)
- [Commits](typhoeus/ethon@v0.11.0...v0.12.0)

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

Author: dependabot-support

Gemfile.lock

@@ -22,13 +22,13 @@ GEM
     em-websocket (0.5.1)
       eventmachine (>= 0.12.9)
       http_parser.rb (~> 0.6.0)
-    ethon (0.11.0)
+    ethon (0.12.0)
       ffi (>= 1.3.0)
     eventmachine (1.2.7)
     execjs (2.7.0)
     faraday (0.15.4)
       multipart-post (>= 1.2, < 3)
-    ffi (1.9.25)
+    ffi (1.10.0)
     forwardable-extended (2.6.0)
     gemoji (3.0.0)
     github-pages (193)