add query smoke test

Just to make sure a basic query works and returns a valid result
expose http status code

return the http status code alongside ok or error, since the exact
status can be important. For example flush needs to behave differently
depending on the status 200 or 201.
added flush and tests

add the ability to flush a couchbase bucket

The basic algorithm is:

1. create a document for reference
2. call flush
3.1 if status is 200 the flush was successful and is done
3.2 if status is 201 the flush was started but is not done yet
4. check for the reference document until it is gone to make sure flush
   has finished
added flush/1

uses the bucket the user connected to as the bucket to flush

Closes #36