Update dataset + handle multiple cities and cantons per zipcode

[kira0269]

This is a PR to solve both issues #46 and #33.

I don't know if you want to keep a "no breaking change promise".
I changed some methods signatures in CantonManager for example.

Tell me if you want me to keep "old" methods and put them in deprecated.

[stefanzweifel]

Thanks for this PR @kira0269! 👏

I'm open to make breaking changes. That's what major versions are here for.
I actually tought about working on these problems myself the last few days; just didn't have the time yet.

As far as I can see, the breaking changes are:

• signature changes in CantonManager
• removal of ZipcodeSearch

That's just something we will have to mention in the release notes and CHANGELOG.

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On first look, the PR looks good. The only thing missing are documentation/examples in the README. Do you want to add them? Or should I contribute them?

Will take a closer look at this this weekend.

[kira0269]

Hi @stefanzweifel

I'll add examples on monday. :)
But feel free to contribute if you want this weekend

[stefanzweifel]

Thanks again for your PR. I've …

• renamed the method to getByZipcodeAndCity() to be more similar to the rest of the API
• updated the CSV import command to use "Ortschaftsname" instead of "Gemeindename". Several cities/villages I know were no longer in the dataset as their name was swallowed by using the "Gemeindename". (For example "Glattpark" and "Glattbrugg" both are valid cities but belong to the same municipality called "Opfikon".)

Going to merge this and release a new major version.

[stefanzweifel]

I was a bit hot-headed and 7124f06 broke the test suite. Will ship a fix soon.