CBIDXT-267: Integrate monster to testrunner

The current implementation assumes that monster tool is installed on the local box and we can run it via python.

All the required files for monster are checkedin and will be modified as required.

Code Example Usage:

x =  JsonGenerator()
map = x.execute_json_data_generator(
    "go run ~/gocode/src/github.com/prataprc/monster/monster/monster.go ",
        key_extension=  "key", bag_dir = "bags/",
            pod_path = "prod/projects.prod", num_items = 10, seed = 1)

print map

Change-Id: I1cbe2020e5b35a3ac44c83538dcd229f0441b7dd
Reviewed-on: http://review.couchbase.org/43524
Reviewed-by: Pratap Chakravarthy <prataprc@couchbase.com>
Reviewed-by: Parag Agarwal <agarwal.parag@gmail.com>
Tested-by: Parag Agarwal <agarwal.parag@gmail.com>