Remove algebra

Algebra is a part of cats as of typelevel/cats#3918

Author: valencik

_data/projects.yml

@@ -1,7 +1,3 @@
-- title: "algebra"
-  category: "Basic type classes"
-  description: "A solid foundation of basic algebra type classes such as groups and rings aiming to serve as a consistent foundation for multiple libraries."
-  github: "https://github.com/non/algebra"
 - title: "argonaut-shapeless"
   description: "Automatic derivation for argonaut"
   github: "https://github.com/alexarchambault/argonaut-shapeless"