Bump knapsack_pro from 1.15.0 to 2.6.0

Bumps [knapsack_pro](https://github.com/KnapsackPro/knapsack_pro-ruby) from 1.15.0 to 2.6.0.
- [Release notes](https://github.com/KnapsackPro/knapsack_pro-ruby/releases)
- [Changelog](https://github.com/KnapsackPro/knapsack_pro-ruby/blob/master/CHANGELOG.md)
- [Commits](https://github.com/KnapsackPro/knapsack_pro-ruby/compare/v1.15.0...v2.6.0)

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

Gemfile

@@ -75,7 +75,7 @@ group :development, :test do
   gem "factory_bot_rails", "~> 4.8.2"
   gem "faker", "~> 1.8.7"
   gem "i18n-tasks", "~> 0.9.31"
-  gem "knapsack_pro", "~> 1.15.0"
+  gem "knapsack_pro", "~> 2.6.0"
   gem "launchy", "~> 2.4.3"
   gem "letter_opener_web", "~> 1.3.4"
   gem "spring", "~> 2.0.1"

Gemfile.lock

@@ -319,7 +319,7 @@ GEM
       activerecord
       kaminari-core (= 1.2.1)
     kaminari-core (1.2.1)
-    knapsack_pro (1.15.0)
+    knapsack_pro (2.6.0)
       rake
     kramdown (2.3.0)
       rexml
@@ -677,7 +677,7 @@ DEPENDENCIES
   jquery-rails (~> 4.4.0)
   jquery-ui-rails (~> 6.0.1)
   kaminari (~> 1.2.1)
-  knapsack_pro (~> 1.15.0)
+  knapsack_pro (~> 2.6.0)
   launchy (~> 2.4.3)
   letter_opener_web (~> 1.3.4)
   mdl (~> 0.11.0)