Add JSON Reporter

Change-Id: Ie7bbeeb6c76bade755d4a1ccd94b7cf15c9f7ed7
Reviewed-on: http://gerrit.causes.com/43243
Tested-by: jenkins <jenkins@causes.com>
Reviewed-by: Shane da Silva <shane.dasilva@brigade.com>
Add JSON reporter example to README

Change-Id: I8f463f94600d76227125491f61759647569b3c25
Reviewed-on: http://gerrit.causes.com/43244
Tested-by: jenkins <jenkins@causes.com>
Reviewed-by: Shane da Silva <shane.dasilva@brigade.com>