Jmeter sampler does not see resources file

I am creating custom sampler for JMeter. I am able to import my jar into library, the sampler is visible within the GUI, but the fields are not displayed properly.

Here is my code.

Custom.java

public class Custom extends AbstractSampler implements TestBean {

  private String email = "";

  public Custom() {
    super();
  }

  public SampleResult sample(Entry entry) {
    SampleResult res = new SampleResult();
    res.setSampleLabel(getName());
    res.setResponseData(("Hello " + getEmail()).getBytes());
    res.setSuccessful(Boolean.TRUE);
    return res;
  }

  public void setEmail(String email){ this.email = email; }
  public String getEmail(){ return email; }
}

CustomBeanInfo.java

public class CustomBeanInfo extends BeanInfoSupport {

  protected CustomBeanInfo() {
    super(Custom.class);

    createPropertyGroup("contact", new String[]{
      "email"
    });

    PropertyDescriptor p = property("email");
    p.setValue(NOT_UNDEFINED, Boolean.TRUE);
    p.setValue(DEFAULT, "asd");
  }
}

CustomResources.properties

displayName=Custom Sampler
email.displayName=Email Address
email.shortDescription=User Email Address
contact.displayName=Contact

And this is how it looks in JMeter GUI. My guess is that the properties file is not correctly attached to sampler or the constructor is not executed.

EDIT 1: Added pom.xml file content

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>

  <groupId>org.apache.jmeter</groupId>
  <artifactId>custom-sampler</artifactId>
  <version>0.2.0-SNAPSHOT</version>
  <packaging>jar</packaging>
  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
  </properties>
  <dependencies>
    <dependency>
      <groupId>org.apache.jmeter</groupId>
      <artifactId>ApacheJMeter_core</artifactId>
      <version>2.10</version>
      <scope>provided</scope>
    </dependency>
  </dependencies>
  <build>
    <resources>
      <resource>
        <directory>src/main/resources</directory>
        <filtering>true</filtering>
      </resource>
    </resources>
  </build>
</project>

EDIT 2: When using sampler (adding it to thread group) following error appears in log

2016/03/25 09:28:23 WARN  - jmeter.testbeans.gui.GenericTestBeanCustomizer: org.apache.jmeter.protocol.java.sampler.Custom#email(java.lang.String) does not appear to have been configured