Eventio

Add support for version 3 of

* PixelSettings (2004)
* TriggerInformatin (2009)
* TelescopeEventHeader (2011)

* Add support for the new eventio type 1216 for atmospheric profiles

* Better error message for `EventIOObject.parse` if called on container object

Merged PRs

* Merge pull request 184 from cta-observatory/improve_parse

* Provide `eventio.__version__`

* Several optimizations result in roughly 5 - 10% faster reading of simtel files
* `EventIOFile` and `EventIOObject` act as true iterators now (do not reset int `__iter__`)
* Removed the hotfix for the memory leak for zstd files, as this was fixed upstream in version 0.11.1

Merged PRs:

* Merge pull request 177 from cta-observatory/update_readme
* Merge pull request 174 from cta-observatory/fix_iterators
* Merge pull request 176 from cta-observatory/remove_zstd_hotfix
* Merge pull request 175 from cta-observatory/gitignore
* Merge pull request 172 from cta-observatory/reorder_ifs
* Merge pull request 171 from cta-observatory/no_init_parsing

* Better string representation of three iact objects
* fix seeking 0 bytes for zstd files