Add a function for checking relex server is reachable or not
Add a function for checking relex server is reachable or not

relex-reachable? can be used as a simple circuit breaker before running
unit or integration tests

andre-senna/opencog,AmeBel/opencog,andre-senna/opencog,andre-senna/opencog,AmeBel/opencog,AmeBel/opencog,AmeBel/opencog,andre-senna/opencog,AmeBel/opencog,AmeBel/opencog,andre-senna/opencog,AmeBel/opencog,andre-senna/opencog,andre-senna/opencog