text: Title: Add suffix "acion" to Spanish SnowballStemmer
  Body: Hi, 
  
  I'm a native Spanish speaker and I've noticed words with suffix "acion" don't get stemmed. (You got right the plural version "aciones", but not the singular one)
  
  Please, add suffix "acion" to Spanish SnowballStemmer
  
  Thank you for your work!