Bump bootstrap from 4.2.1 to 4.3.1 in /WorldHistoryBookStore

Bumps bootstrap from 4.2.1 to 4.3.1.

---
updated-dependencies:
- dependency-name: bootstrap
  dependency-type: direct:production
...

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

Author: dependabot[bot]

WorldHistoryBookStore/packages.config

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <packages>
   <package id="Antlr" version="3.4.1.9004" targetFramework="net461" />
-  <package id="bootstrap" version="4.2.1" targetFramework="net461" />
+  <package id="bootstrap" version="4.3.1" targetFramework="net461" />
   <package id="EntityFramework" version="6.2.0" targetFramework="net461" />
   <package id="jQuery" version="3.3.1" targetFramework="net461" />
   <package id="jQuery.Validation" version="1.17.0" targetFramework="net461" />