Qiskit IBMQ Provider 0.4.6

Added

• IBMQJob now has a new method wait_for_final_state() that blocks
  until the job finishes. One of its parameters is a callback function
  that it will invoke after every query to provide feedback. (#529)
• IBMQBackend now has a new method active_jobs(). The method returns the
  jobs submitted to a backend that are currently in an unfinished status.
  Note the unfinished jobs returned for the backend are given for a specific
  provider (i.e. a specific backend with a specific provider). (#521)
• QueueInfo (returned by IBMQJob.queue_info()) now has a new method:
  format(). The method returns a formatted string of the queue information.
  (#515)
• IBMQJob now has three new methods: done(), running(), and
  cancelled(). The methods are used to indicate the job status. (#494)
• backend.run() now accepts an optional job_tags parameter. If
  specified, the job_tags are assigned to the job, which can also be used
  as a filter in backend.jobs(). (#511)
• IBMQBackend now has two new methods: job_limit() and
  remaining_job_counts(). job_limit() returns the job limit for a
  backend, which includes the current number of active jobs you have on
  the backend and the the maximum number of active jobs you can have on
  it. remaining_job_counts() returns the number of remaining jobs that
  could be submitted to the backend before the maximum limit on active
  jobs is reached. Note the job limit for a backend is given for a specific
  provider (i.e. a specific backend with a specific provider). (#513)
• IBMQJobManager now has a new method retrieve_job_set() that allows
  you to retrieve a previously submitted job set using the job set ID.
  A job set ID can be retrieved using the new job_set.job_set_id()
  method. (#514)

Changed

• The Exception hierarchy has been refined with more specialized classes.
  You can, however, continue to catch their parent exceptions (such
  as IBMQAccountError). Also, the exception class IBMQApiUrlError
  has been replaced by IBMQAccountCredentialsInvalidUrl and
  IBMQAccountCredentialsInvalidToken. (#480)

Deprecated

• The use of proxy urls without a protocol (e.g. http://) is deprecated
  due to recent Python changes. (#538)