Bump bootstrap from 4.1.3 to 4.3.1

Bumps [bootstrap](https://github.com/twbs/bootstrap-rubygem) from 4.1.3 to 4.3.1.
- [Release notes](https://github.com/twbs/bootstrap-rubygem/releases)
- [Changelog](https://github.com/twbs/bootstrap-rubygem/blob/master/CHANGELOG.md)
- [Commits](twbs/bootstrap-rubygem@v4.1.3...v4.3.1)

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

Gemfile

@@ -32,7 +32,7 @@ gem 'jbuilder', '~> 2.8'
 # Use Capistrano for deployment
 # gem 'capistrano-rails', group: :development
 
-gem 'bootstrap', '~> 4.1.0'
+gem 'bootstrap', '~> 4.3.1'
 gem 'jquery-rails'
 
 gem 'high_voltage'

Gemfile.lock

@@ -47,16 +47,16 @@ GEM
     ansi (1.5.0)
     arel (9.0.0)
     ast (2.4.0)
-    autoprefixer-rails (9.4.2)
+    autoprefixer-rails (9.5.1.1)
       execjs
     bcrypt (3.1.12)
     bcrypt (3.1.12-x64-mingw32)
     bcrypt (3.1.12-x86-mingw32)
     bindex (0.5.0)
-    bootstrap (4.1.3)
-      autoprefixer-rails (>= 6.0.3)
-      popper_js (>= 1.12.9, < 2)
-      sass (>= 3.5.2)
+    bootstrap (4.3.1)
+      autoprefixer-rails (>= 9.1.0)
+      popper_js (>= 1.14.3, < 2)
+      sassc-rails (>= 2.0.0)
     builder (3.2.3)
     byebug (10.0.2)
     capybara (3.12.0)
@@ -96,9 +96,9 @@ GEM
     factory_bot_rails (4.11.1)
       factory_bot (~> 4.11.1)
       railties (>= 3.0.0)
-    ffi (1.9.25)
-    ffi (1.9.25-x64-mingw32)
-    ffi (1.9.25-x86-mingw32)
+    ffi (1.11.1)
+    ffi (1.11.1-x64-mingw32)
+    ffi (1.11.1-x86-mingw32)
     globalid (0.4.2)
       activesupport (>= 4.2.0)
     high_voltage (3.1.0)
@@ -192,8 +192,8 @@ GEM
     rainbow (3.0.0)
     rake (12.3.2)
     rb-fsevent (0.10.3)
-    rb-inotify (0.9.10)
-      ffi (>= 0.5.0, < 2)
+    rb-inotify (0.10.0)
+      ffi (~> 1.0)
     regexp_parser (1.3.0)
     responders (2.4.0)
       actionpack (>= 4.2.0, < 5.3)
@@ -243,7 +243,7 @@ GEM
       unicode-display_width (~> 1.4.0)
     ruby-progressbar (1.10.0)
     rubyzip (1.2.2)
-    sass (3.7.2)
+    sass (3.7.4)
       sass-listen (~> 4.0.0)
     sass-listen (4.0.0)
       rb-fsevent (~> 0.9, >= 0.9.4)
@@ -254,6 +254,15 @@ GEM
       sprockets (>= 2.8, < 4.0)
       sprockets-rails (>= 2.0, < 4.0)
       tilt (>= 1.1, < 3)
+    sassc (2.0.1)
+      ffi (~> 1.9)
+      rake
+    sassc-rails (2.1.1)
+      railties (>= 4.0.0)
+      sassc (>= 2.0)
+      sprockets (> 3.0)
+      sprockets-rails
+      tilt
     selenium-webdriver (3.141.0)
       childprocess (~> 0.5)
       rubyzip (~> 1.2, >= 1.2.2)
@@ -314,7 +323,7 @@ PLATFORMS
   x86-mingw32
 
 DEPENDENCIES
-  bootstrap (~> 4.1.0)
+  bootstrap (~> 4.3.1)
   byebug
   capybara (~> 3.12)
   cocoon