Fix weird version warning

Whenever IGB builds, mvn prints loads of warning messages that look like this:

[INFO] Scanning for projects...
[WARNING]
[WARNING] Some problems were encountered while building the effective model for org.lorainelab.igb:heatmap-editor:bundle:9.1.0
[WARNING] The expression $

{version} is deprecated. Please use ${project.version} instead.
[WARNING]
[WARNING] Some problems were encountered while building the effective model for org.lorainelab.igb:affymetrix-common:bundle:9.1.0
[WARNING] The expression ${version}

is deprecated. Please use $

{project.version}

instead.

and on and on like this for every module in the project.

Please investigate:

• Why is this happening?
• How can we fix it?