chore: replace gitter badge with slack
chore: replace gitter badge with slack

pact-foundation/pact_broker,pact-foundation/pact_broker,pact-foundation/pact_broker,tancnle/pact_broker,tancnle/pact_broker,tancnle/pact_broker,pact-foundation/pact_broker,tancnle/pact_broker