Creating a new local maven repo (Enterprise) following these instructions:
http://documentation.magnolia-cms.com/display/DOCS/Maven+init

Building the ui project produces this error:
[INFO] ------------------------------------------------------------------------
[ERROR] BUILD ERROR
[INFO] ------------------------------------------------------------------------
[INFO] Failed to resolve artifact.

Missing:
----------
1) org.vaadin.addons:icepush:jar:0.5.3

Try downloading the file manually from the project website.

Then, install it using the command:
mvn install:install-file -DgroupId=org.vaadin.addons -DartifactId=icepush -Dversion=0.5.3 -Dpackaging=jar -Dfile=/path/to/file

Alternatively, if you host your own repository you can deploy the file there:
mvn deploy:deploy-file -DgroupId=org.vaadin.addons -DartifactId=icepush -Dversion=0.5.3 -Dpackaging=jar -Dfile=/path/to/file -Durl=[url] -DrepositoryId=[id]

Path to dependency:
1) info.magnolia.ui:magnolia-ui-vaadin-integration:jar:5.0.1
2) org.vaadin.addons:icepush:jar:0.5.3

----------
1 required artifact is missing.

for artifact:
info.magnolia.ui:magnolia-ui-vaadin-integration:jar:5.0.1

from the specified remote repositories:
central (http://repo1.maven.org/maven2),
magnolia.nexus.enterprise (http://nexus.magnolia-cms.com/content/groups/enterprise/)

[INFO] ------------------------------------------------------------------------
[INFO] For more information, run Maven with the -e switch