[EPE-260] Prevent builds to run if they are not using a version greater than g++ 8.0. g++7.5 will fail to build the tests.
[EPE-260] Prevent builds to run if they are not using a version greater than g++ 8.0.
g++7.5 will fail to build the tests.

EOSIO/eos,EOSIO/eos,EOSIO/eos,EOSIO/eos,EOSIO/eos