Add Czech and Slovak translation.

[mstefany]

This trivial commit adds Czech and Slovak translations. I use Home Assistant in Czech language and my brother in Slovak so this would be nice additions for us.

[AitorDB]

Hey! Apologies for taking so long to answer, I'm a little short of time lately. In the develop branch there was already a Czech and Slovak translations, however there's a few differences, would you mind taking a look and see if those are correct or should I change anything?

Thanks!

[mstefany]

@AitorDB nice, I am actually OK with both translations, I would only adjust the error message, since name of the integration itself is translated here:
https://github.com/home-assistant/core/blob/4f7e405a2c692f1f4a0397b0ec53d58b6c26cdab/homeassistant/components/sun/translations/cs.json#L8
and here:
https://github.com/home-assistant/core/blob/4f7e405a2c692f1f4a0397b0ec53d58b6c26cdab/homeassistant/components/sun/translations/sk.json#L8

[leroyloren]

This commit is inaccurate the constants are case sensitive and in addition it is useless to use the word "Sun (slunce)" when it is clear from the integration.

This one is Ok.
#98

{
  "Azimuth": "Azimut",
  "Dawn": "Svítání",
  "Dusk": "Soumrak",
  "Elevation": "Výška",
  "Noon": "Zenit",
  "Sunrise": "Východ",
  "Sunset": "Západ",
  "errors": {
    "SunIntegrationNotFound": "Integrace Slunce nenalezena"
  }
}