Update dependencies to fix several security vulnerabilities

[albuch]

The current version of TeamDojo has the following vulnerable dependencies included.

• org.dom4j_dom4j version 1.6.1 has 2 vulernabilities
• io.undertow_undertow-core version 1.4.26.Final has 7 vulnerabilities.
• com.fasterxml.jackson.core_jackson-databind version 2.9.8 has 31 vulnerabilities.
• com.fasterxml.jackson.core_jackson-databind version 2.9.5 has 42 vulnerabilities.
• org.apache.logging.log4j_log4j-api version 2.10.0 has 1 vulnerability.

I've tried to provide a pull request, but due to the very outdated and unsupported version of JHipster (v2.1.1) as well as dependencies to other needed upgrades (Gradle, Node-Plugin etc.) I couldn't manage upgrading the stack in a timely manner.