Authorised Travis.
Added tests for TransactionExecutor.
Added tests for CallbackTransaction.
Added tests for TransactionTrait.
Added tests for InternalTransactionTrait.
Added tests for TransactionHelper.
Readme [ci skip]
README.md [ci skip]
Executor interface was not being used.
Added TransactionExecutorInterface::executeCallable()
Removed cruft, keep it simple.
Improved documentation.
Typo [ci skip]
Executor now passes number of remaining attempts to callback.
Implemented TransactionExecutor::__invoke().
Removed unused dependencies.
Improved links in readme [ci skip]
Archer auth.
Updated README links.
Bumped version and updated changelog.