update changelog with 0.16.0 release
update changelog with 0.16.0 release

silviacanessa/oq-hazardlib,silviacanessa/oq-hazardlib,gem/oq-engine,vup1120/oq-hazardlib,silviacanessa/oq-hazardlib,gem/oq-hazardlib,gem/oq-hazardlib,gem/oq-engine,silviacanessa/oq-hazardlib,rcgee/oq-hazardlib,gem/oq-hazardlib,rcgee/oq-hazardlib,vup1120/oq-hazardlib,gem/oq-engine,vup1120/oq-hazardlib,gem/oq-engine,gem/oq-engine