wikimedia/restbase-cassandra — pull request #48 by hardikj (2014-12-29 22:10:49+00:00)
Title: fix getSchema to return null for unknown keyspace

Get Schema seems to throw an error when called upon a keyspace that does not exists, it should return null instead, below is the Error trace I get on calling getSchema on keyspace that does not exist. this pull fix this issue

```
{ [ResponseError: Keyspace local_test_cassandra_restbase_T_simpleTable does not exist]
stack: 'Error\n at FrameReader.readError (/home/hardikj/rashomon-cassandra/node_modules/cassandra-driver/lib/readers.js:291:13)\n
at Parser.parseError (/home/hardikj/rashomon-cassandra/node_modules/cassandra-driver/lib/streams.js:185:45)\n at Parser.parseBody (/home/hardikj/rashomon-cassandra/node_modules/cassandra-driver/lib/streams.js:167:19)\n
at Parser._transform (/home/hardikj/rashomon-cassandra/node_modules/cassandra-driver/lib/streams.js:101:10)\n at Parser.Transform._read (_stream_transform.js:179:10)\n
at Parser.Transform._write (_stream_transform.js:167:12)\n at doWrite (_stream_writable.js:265:12)\n at writeOrBuffer (_stream_writable.js:252:5)\n at Parser.Writable.write (_stream_writable.js:197:11)\n
at Protocol.ondata (_stream_readable.js:539:20)\n at Protocol.emit (events.js:107:17)\n
at readableAddChunk (_stream_readable.js:162:16)\n at Protocol.Readable.push (_stream_readable.js:125:10)\n at Protocol.Transform.push (_stream_transform.js:140:32)\n
at Protocol.transformChunk (/home/hardikj/rashomon-cassandra/node_modules/cassandra-driver/lib/streams.js:76:8)\n
at Protocol._transform (/home/hardikj/rashomon-cassandra/node_modules/cassandra-driver/lib/streams.js:27:10)\n at Protocol.Transform._read (_stream_transform.js:179:10)\n
at Protocol.Transform._write (_stream_transform.js:167:12)\n
at doWrite (_stream_writable.js:265:12)\n
at writeOrBuffer (_stream_writable.js:252:5)\n
at Protocol.Writable.write (_stream_writable.js:197:11)\n
at Socket.ondata (_stream_readable.js:539:20)\n
at Socket.emit (events.js:107:17)\n
at readableAddChunk (_stream_readable.js:162:16)\n
at Socket.Readable.push (_stream_readable.js:125:10)\n
at TCP.onread (net.js:514:20)\n (event loop)\n
at RequestHandler.send (/home/hardikj/rashomon-cassandra/node_modules/cassandra-driver/lib/request-handler.js:124:11)\n
at Client._getPrepared (/home/hardikj/rashomon-cassandra/node_modules/cassandra-driver/lib/client.js:399:11)\n
at /home/hardikj/rashomon-cassandra/node_modules/cassandra-driver/lib/client.js:313:12\n
at fn (/home/hardikj/rashomon-cassandra/node_modules/async/lib/async.js:641:34)\n
at Immediate._onImmediate (/home/hardikj/rashomon-cassandra/node_modules/async/lib/async.js:557:34)
at processImmediate [as _immediateCallback] (timers.js:374:17)',
name: 'ResponseError',
message: 'Keyspace local_test_cassandra_restbase_T_simpleTable does not exist',
info: 'Represents an error message from the server',
code: 8704,
query: 'select * from "local_test_cassandra_restbase_T_simpleTable"."meta"' }
```