Integration Tests now use -Dtests.config=/path/to/elasticsearch.yml

Add tests documentation

(cherry picked from commit 2725084)
Fix IT test for #50

(cherry picked from commit 0685df2)
Update to Twitter4J 4.0.2

Closes #61.

(cherry picked from commit f6b628d)
Add note regarding User Stream integration test

(cherry picked from commit 3b79546)
Generate default mapping even if index already exists

If you create in advance your own index:

```
PUT /myindex
```

When the river starts, it does not add the default mapping.

Closes #62.

(cherry picked from commit 188e35e)
Support geo location array format

Closes #51.

(cherry picked from commit f727f29)
Update to elasticsearch 1.3.0

Closes #53.

(cherry picked from commit b3eb6af)