update changelog for release 0.7.11
update changelog for release 0.7.11

pact-foundation/pact-reference,pact-foundation/pact-mock-server,pact-foundation/pact-reference,pact-foundation/pact-reference,pact-foundation/pact-reference,pact-foundation/pact-reference,pact-foundation/pact-reference,pact-foundation/pact-reference,pact-foundation/pact-reference