Fix name and meta fields in Ballots

[mdbrnowski]

There is a problem in all ...Ballot initializations: the name and meta fields are lost. These fields are correctly passed to Ballot.__init__(), but they are missing in Abstract...Ballot.__init__(), which resets them.

For example, the code:

from pabutools.election.instance import get_random_instance
from pabutools.election.profile import get_random_approval_profile
instance = get_random_instance(3, 1, 10)
profile = get_random_approval_profile(instance, 3)
for ballot in profile:
    print(ballot.name)

currently prints three empty lines.

After this PR, it correctly prints:

RandomAppBallot 0
RandomAppBallot 1
RandomAppBallot 2

[mdbrnowski]

The tests fail due to an HTTPError -- this seems to be an issue with pabulib.org [url].