Do not expect much order in the objects of the file

[dneise]

This should show the same features as e.g. #138 but it does not expect any particular order in the objects anymore .. at least not so much order as we expected in the master.

This fixes #132, #135 and #137.

The test files needed to show this are in total 60MB! I was unable to make them smaller :-(

The tests showing that this branch fixes the upper issues are:

from collections import defaultdict


# GH: 137
def test_simtel_file_can_read_file_with_strange_structure():
    from eventio import SimTelFile
    path = 'testfile_eventio_issue_137.simtel.gz'
    for event in SimTelFile(path):
        pass
    assert event


# GH: 135
def test_file_really_had_cam_orga_v2():
    from eventio import EventIOFile
    from eventio.simtel.objects import CameraOrganization
    path = 'has_CameraOrganization_v2.simtel.gz'
    cam_orga = []
    for o in EventIOFile(path):
        if isinstance(o, CameraOrganization) and o.header.version == 2:
            cam_orga.append(o)
    assert cam_orga


# GH: 135
def test_SimTelFile_can_read_this_file():
    from eventio import SimTelFile
    path = 'has_CameraOrganization_v2.simtel.gz'
    f = SimTelFile(path)
    assert f.header


# GH: 132
def test_SimTelFile_can_read_multiple_runs_from_file():
    path = 'run1011_merged.dst0.simtel.gz'
    from eventio import SimTelFile
    events_by_run = defaultdict(int)
    f = SimTelFile(path)
    for e in f:
        events_by_run[f.header['run']] += 1

    assert events_by_run[10] == 301
    assert events_by_run[11] == 315

[dneise]

For these tests to work you need a couple of files, which I prepared for this PR.
But I have no idea where to put the files.

https://we.tl/t-19mavjGbGt

[dneise]

Showing that the tests work .. without uploading the test files to github.
https://youtu.be/IH38-ng4JCY