Build and test on Linux and Mac OSX.

Lets see if this passes on Travis-CI. Locally I got:

```
    [junit] java.lang.Error: The user deployment directory /Users/dblock/Library/Caches/Java does not exist; save Java Control Panel or Web Start settings to initialize it
    [junit] 	at com.sun.jna.WebStartTest.findDeploymentProperties(WebStartTest.java:344)
    [junit] 	at com.sun.jna.WebStartTest.runBare(WebStartTest.java:362)
    [junit] 
```

So maybe this will need more work.