Drools runtime engine not working in IntelliJ IDEA

I am using IntelliJ IDEA Ultimate 17.2. 

I tried running several demo projects of Drools, they compile and run but the DRL files in the resource folder are not being processed.

The result set is unchanged as though the rule is not being fired. If I run the exact same code in Eclipse, it works as expected.

I verified that IntelliJ is able to locate the DRL file by dynamically loading it as follows:

kbuilder.add(ResourceFactory.newClassPathResource("booking.drl", BookingTest.class), ResourceType.DRL);

Altering the path results in a runtime exception, so it appears as though the Drools Runtime Engine does not work in IntelliJ.

Other attempts involved creating a project with Drools 6.2 Framework, altering the Maven dependency for drools-compiler to versions 6.2.0.Final and 7.1.0.Final.

src/main/java.com.sample.BookingTest:

package com.sample;

import org.kie.api.KieServices;
import org.kie.api.runtime.KieContainer;
import org.kie.api.runtime.KieSession;

/**
 * This is a sample class to launch a rule.
 */
public class BookingTest {

    public static final void main(String[] args) {
        try {
            // load up the knowledge base
            KieServices ks = KieServices.Factory.get();
            KieContainer kContainer = ks.getKieClasspathContainer();
            KieSession kSession = kContainer.newKieSession("ksession-rules");

            // go !
            Booking booking = new Booking();
            booking.setDiscount(true);
            booking.setPrice(50);
            System.out.println("Initial price: " + booking.getPrice());
            kSession.insert(booking);
            kSession.fireAllRules();
            System.out.println("New price: " + booking.getPrice());
        } catch (Throwable t) {
            t.printStackTrace();
        }
    }

    public static class Booking {

        boolean discount;
        int price;

        public boolean applyDiscount() {
            return discount;
        }

        public void setDiscount(boolean discount) {
            this.discount = discount;
        }

        public void setPrice(int price) {
            this.price = price;
        }

        public int getPrice() {
            return price;
        }
    }
}

src/main/resources/booking.drl:

package com.sample

import com.sample.BookingTest.Booking;

rule "Apply discount"
    when
        b : Booking( applyDiscount()==true )
    then
        System.out.println("Apply discount rule fired");
        b.setPrice(60);
end

src/main/resources/META-INF/kmodule.xml:

<?xml version="1.0" encoding="UTF-8"?>
<kmodule xmlns="http://jboss.org/kie/6.0.0/kmodule">
 <kbase name="rules" packages="rules">
 <ksession name="ksession-rules"/>
 </kbase>
</kmodule>

Eclipse output:
Initial price: 50
Apply discount rule fired
New price: 60

IntelliJ Idea output:
Initial price: 50
New price: 50

Any ideas?