Deletes the pipeline specified by the key
		Args:
			returns 	(status code for the DELETE request, success message dict)
						expect (200 , {'success': 'true'}) for successful execution}

def delete_pipeline(self, pipeline_key):
		'''Deletes the pipeline specified by the key
		Args:
			returns 	(status code for the DELETE request, success message dict)
						expect (200 , {'success': 'true'}) for successful execution}
		'''
		if pipeline_key:
			uri = '/'.join([
							self.api_uri,
							self.pipelines_suffix,
							pipeline_key
							])
			return self._req('delete', uri)
		else:
			return requests.codes.bad_request, None