The README file doesn't reflect the actual endpoint implemented to GE…
The README file doesn't reflect the actual endpoint implemented to GE…

…T the Batch Logs as well as the response to GET all Batches.

The current documentation has the following mistakes:
1. Points to `GET /batches/{batchId}/logs` when in fact is `GET /batches/{batchId}/log`.
2. The `GET /batches` refers to a response that contains `batches` when in fact returns `sessions`.

Closes #106

ajbozarth/incubator-livy,meisam/incubator-livy,ajbozarth/incubator-livy,meisam/incubator-livy,meisam/incubator-livy,ajbozarth/incubator-livy,meisam/incubator-livy,ajbozarth/incubator-livy,meisam/incubator-livy,meisam/incubator-livy,ajbozarth/incubator-livy,ajbozarth/incubator-livy