Bump chartkick from 3.3.1 to 3.4.0

Bumps [chartkick](https://github.com/ankane/chartkick) from 3.3.1 to 3.4.0.
- [Release notes](https://github.com/ankane/chartkick/releases)
- [Changelog](https://github.com/ankane/chartkick/blob/master/CHANGELOG.md)
- [Commits](ankane/chartkick@v3.3.1...v3.4.0)

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

Gemfile

@@ -82,7 +82,7 @@ gem 'serrano', '~> 0.6.0'
 gem 'pdf-reader', '~> 2.2'
 
 # UI/UX
-gem 'chartkick', '~> 3.3'
+gem 'chartkick', '~> 3.4'
 gem 'groupdate', '~> 4.2'
 gem 'dropzonejs-rails', '~> 0.8.1'
 gem 'kaminari', '~> 1.2.0'

Gemfile.lock

@@ -115,7 +115,7 @@ GEM
       rack-test (>= 0.6.3)
       regexp_parser (~> 1.5)
       xpath (~> 3.2)
-    chartkick (3.3.1)
+    chartkick (3.4.0)
     childprocess (3.0.0)
     chronic (0.10.2)
     chunky_png (1.3.11)
@@ -566,7 +566,7 @@ DEPENDENCIES
   bundler (~> 2.0)
   byebug (~> 11.1)
   capybara (~> 3.18)
-  chartkick (~> 3.3)
+  chartkick (~> 3.4)
   chronic (~> 0.10.2)
   chunky_png (~> 1.3.11)
   citeproc-ruby (~> 1.1.10)