Using GWT Bootstrap SNAPSHOTS version with Maven

First add a repository to your pom.xml

 <repository>
     <id>sonatype</id>
     <url>http://oss.sonatype.org/content/repositories/snapshots</url>
     <snapshots><enabled>true</enabled></snapshots>
     <releases><enabled>false</enabled></releases>
 </repository>

Then add the dependency:

<dependency>
    <groupId>com.github.gwtbootstrap</groupId>
    <artifactId>gwt-bootstrap</artifactId>
    <version>2.2.1.0-SNAPSHOT</version>
    <scope>provided</scope>
</dependency>

Now, just run mvn process-resources to download the jar files. You can also take a look at Javadocs to learn how to use it.