Golem-core

What's Changed
* AggregatingDemandManager by approxit in https://github.com/golemfactory/golem-core-python/pull/137
* Validate debit notes and invoices by lucekdudek in https://github.com/golemfactory/golem-core-python/pull/139

**Full Changelog**: https://github.com/golemfactory/golem-core-python/compare/0.5.0...0.6.0

What's Changed
* Buffer refactor by approxit in https://github.com/golemfactory/golem-core-python/pull/132
* Error propagation by approxit in https://github.com/golemfactory/golem-core-python/pull/134
* Async get_expiration_date in Demand and Proposal resources by approxit in https://github.com/golemfactory/golem-core-python/pull/135

**Full Changelog**: https://github.com/golemfactory/golem-core-python/compare/0.4.0...0.5.0

What's Changed
* Add `ErrorReportingQueue` and use it in RefreshingDemandManager by shadeofblue in https://github.com/golemfactory/golem-core-python/pull/130
* Add AddMidAgreementPayments negotiator by lucekdudek in https://github.com/golemfactory/golem-core-python/pull/131

**Full Changelog**: https://github.com/golemfactory/golem-core-python/compare/0.3.2...0.4.0

What's Changed
* RejectIfCostsExceeds bounds check fix by mateuszsrebrny in https://github.com/golemfactory/golem-core-python/pull/128

New Contributors
* mateuszsrebrny made their first contribution in https://github.com/golemfactory/golem-core-python/pull/128

**Full Changelog**: https://github.com/golemfactory/golem-core-python/compare/0.3.1...0.3.2

What's Changed
* LinearAverageCostPricing initial_price calculation fix by approxit in https://github.com/golemfactory/golem-core-python/pull/126


**Full Changelog**: https://github.com/golemfactory/golem-core-python/compare/0.3.0...0.3.1

What's Changed
* Handle exception on demand unsubscribe by lucekdudek in https://github.com/golemfactory/golem-core-python/pull/118
* simplify the PayloadSyntaxParser usage by shadeofblue in https://github.com/golemfactory/golem-core-python/pull/119
* Add missing prop and const by lucekdudek in https://github.com/golemfactory/golem-core-python/pull/115
* remove args and kwargs from refreshing demand manager by shadeofblue in https://github.com/golemfactory/golem-core-python/pull/121
* move demand/proposal retrieval into more sensible location by shadeofblue in https://github.com/golemfactory/golem-core-python/pull/122
* Empty constraint support and per cpu pricings by approxit in https://github.com/golemfactory/golem-core-python/pull/123
* fix the integration tests by shadeofblue in https://github.com/golemfactory/golem-core-python/pull/124

**Full Changelog**: https://github.com/golemfactory/golem-core-python/commits/0.3.0