Move Stat and clarify example command line

- Stat is now in com.google.cloud.examples.nio (following the gcloud ->
cloud move)
- Added version for appassembler to remove warning
- added 'mvn install' to instructions because it's necessary.

Author: jean-philippe-martin

gcloud-java-examples/README.md

@@ -37,7 +37,8 @@ To run examples from your command line:
 
 2. Set your current project using `gcloud config set project PROJECT_ID`. This step is not necessary for `ResourceManagerExample`.
 
-3. Compile using Maven: `cd gcloud-java-examples` in command line from your base project directory and then `mvn package appassembler:assemble -DskipTests -Dmaven.javadoc.skip=true  -Dmaven.source.skip=true`.
+3. Compile using Maven: `mvn install -DskipTests -Dmaven.javadoc.skip=true -Dmaven.source.skip=true` in command line from your base project directory
+   then `cd gcloud-java-examples` and finally `mvn package appassembler:assemble -DskipTests -Dmaven.javadoc.skip=true -Dmaven.source.skip=true`.
 
 4. Run an example from the command line using the Maven-generated scripts.
 

gcloud-java-examples/pom.xml

@@ -48,6 +48,7 @@
       <plugin>
         <groupId>org.codehaus.mojo</groupId>
         <artifactId>appassembler-maven-plugin</artifactId>
+        <version>1.10</version>
         <configuration>
           <programs>
             <program>