In Maven parent project, in dependency management, we should only declare which versions of 3rd party jars we want to use but not force any scope.
It makes then more obvious in modules what is exactly the scope of any dependency.
For example, one could imagine importing `jimfs` as a `compile` dependency in another module/plugin with:
```xml
<dependency>
<groupId>com.google.jimfs</groupId>
<artifactId>jimfs</artifactId>
</dependency>
```
But it won't work as expected as the default maven `scope` should be `compile` but here it's `test` as defined in the parent project.
So, if you want to use this lib for tests, you should simply define:
```xml
<dependency>
<groupId>com.google.jimfs</groupId>
<artifactId>jimfs</artifactId>
<scope>test</scope>
</dependency>
```
We also remove `maven-s3-wagon` from gce plugin as it's not used.
This commit adds an additioal jar that is shaded and keeps all the
artifacts that are used by default on the server-side unshaded. Users
that need a shaded jar can now use the `shaded` classifyer to pull
the shaded minimized jar in instead. Including the shaded jar in a
downstream project looks like this:
```XML
<dependency>
<groupId>org.elasticsearch</groupId>
<artifactId>elasticsearch</artifactId>
<classifier>shaded</classifier>
</dependency>
```