Remove eureka-client dependency from turbine-web

This dependency appears to have been added in error (it belongs only in
turbine-contrib). It also currently stops turbine-war from being
installed or deployed, since the lack of version number (on this
dependency) causes Gradle to create an invalid pom.xml for turbine-web.
Merge pull request #35 from joelittlejohn/invalid-dependency

Remove eureka-client dependency from turbine-web