Maven Compile Warning for SuppressFBWarnings

### Problem:

Introducing the dependency on `aws-encryption-sdk-java` introduces compile warnings about `edu.umd.cs.findbugs.annotations.SuppressFBWarnings`

For example:
```
Cannot find annotation method 'value()' in type 'edu.umd.cs.findbugs.annotations.SuppressFBWarnings': class file for edu.umd.cs.findbugs.annotations.SuppressFBWarnings not found
```

### Solution:

Options:
* Change the scope of the `com.google.code.findbugs` to compile.
* Document the potential warnings and suggest fixes like declaring dependencies in your own project

### Out of scope:

I'm sure there are different options for handling this and they may vary depending on the build tool being used.