meta: add tags for 1.0.0 and 1.0.1

fix: more graceful behavior on connection closure/failure

meta: remove composer.lock

It doesn't actually make sense for a library package.

fix: reduce default TTR to 1h

The maximum value is close to 68 years, which is unreasonable given that
under Beanstalk it's not possible to list or interact with reserved jobs
that don't belong to the current connection.

test: add tests

This is mostly an integration test because it relies on an actual
Beanstalkd connection, but it did help uncover a couple of issues that
were fixed in a previous commit.

fix: a couple of bugs

initial checkin