Don't let dependabot update to Jersey 3

Resolves #35

Change-Id: Icd1e507904d45e452ea393a3eba8510fbfbd4aeb
diff --git a/.github/dependabot.yml b/.github/dependabot.yml
index 3390852..8d43cbf 100644
--- a/.github/dependabot.yml
+++ b/.github/dependabot.yml
@@ -12,4 +12,7 @@
       - dependency-name: "org.eclipse.jetty:jetty-servlet"
         versions:
           - ">= 10.0.0"
+      - dependency-name: "jersey.version"
+        versions:
+          - ">= 3"
     open-pull-requests-limit: 50