Fix undefined property bug

[chanseokoh]

Fixes#633.

[chanseokoh]

I'll fix the test.

[lukecwik]

@huygaa11 Should this be merged back into Apache Beam?

[chanseokoh]

ping

[huygaa11]

@lukecwik yes, I can do that in a consequent PR.

[huygaa11]

@chanseokoh If you would like to contribute to Beam, feel free to send a PR to beam repo. Let me know if you are interested :).

Here is the file in Beam:
https://github.com/apache/beam/blob/master/sdks/java/maven-archetypes/starter/src/main/resources/archetype-resources/pom.xml

[chanseokoh]

@huygaa11 sure, let me do that.

[chanseokoh]

@huygaa11 there's some gradle stuff that I don't understand, so I'll just create a new issue and leave it to you.

[huygaa11]

No worries. Thanks for looking into it.

[chanseokoh]

On the Beam repo, I find

build_rules.gradle: maven_exec_plugin: "maven-plugins:maven-exec-plugin:1.6.0",

sdks/java/maven-archetypes/examples/build.gradle: 'maven-exec-plugin.version': dependencies.create(project.library.maven.maven_exec_plugin).getVersion(),

I wonder if they should be exec-maven-plugin in both cases.

Do note that you'll find a lot of instances of maven-exec-plugin with git grep maven-exec-plugin.

[lukecwik]

Sure, swapping so the property name better aligns with the name of the plugin makes sense.