Bump bootstrap from 4.1.2 to 4.1.3

Bumps [bootstrap](https://github.com/twbs/bootstrap-rubygem) from 4.1.2 to 4.1.3.
- [Release notes](https://github.com/twbs/bootstrap-rubygem/releases)
- [Changelog](https://github.com/twbs/bootstrap-rubygem/blob/master/CHANGELOG.md)
- [Commits](twbs/bootstrap-rubygem@v4.1.2...v4.1.3)

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

Author: dependabot-support

Gemfile.lock

@@ -55,7 +55,7 @@ GEM
       execjs
     bcrypt (3.1.12)
     bindex (0.5.0)
-    bootstrap (4.1.2)
+    bootstrap (4.1.3)
       autoprefixer-rails (>= 6.0.3)
       popper_js (>= 1.12.9, < 2)
       sass (>= 3.5.2)
@@ -151,7 +151,7 @@ GEM
     parser (2.5.1.2)
       ast (~> 2.4.0)
     pg (1.0.0)
-    popper_js (1.12.9)
+    popper_js (1.14.3)
     powerpack (0.1.2)
     puma (3.12.0)
     rack (2.0.5)