Technically they are being classified as fungus, so it's not so trivial to consider them animals. You can safely drink yeast and still be vegan.

About cider, I have no idea if they are vegan-friendly or not, but if they are, please consider French cider brands. They typically are a very different beverage than what is considered cider in the international (or British?) meaning. A lot less sugar, and ultimately a totally different taste. While French cider (either from Brittany or Normandy, the two competing regions in this regard) is one of my favorite light drinks, I can't even finish a glass of the sweeter ciders from Bulmers, Magners or Aspall, which shows that they really are distinct types of ciders.