Update bootstrap from 3.3.7 to 3.4.0

Seems like finally there is a new bootstrap version for old version 3.

This patch implements this new version with CodiMD and this way fixes
some possible security issues in the frontend code.

See:
https://snyk.io/vuln/SNYK-JS-BOOTSTRAP-72889
https://snyk.io/vuln/SNYK-JS-BOOTSTRAP-72890

Signed-off-by: Sheogorath <sheogorath@shivering-isles.com>

package.json

@@ -24,7 +24,7 @@
     "azure-storage": "^2.7.0",
     "base64url": "^3.0.0",
     "body-parser": "^1.15.2",
-    "bootstrap": "^3.3.7",
+    "bootstrap": "^3.4.0",
     "bootstrap-validator": "^0.11.8",
     "chance": "^1.0.4",
     "cheerio": "^0.22.0",