Licence update to MIT

Author: Dzuchun

Cargo.toml

@@ -7,7 +7,8 @@ description = "`nalgebra` storage implementation backed by `generic_array`"
 documentation = "https://dzuchun.github.io/generic-array-storage/generic_array_storage/index.html"
 readme = "README.md"
 repository = "https://github.com/Dzuchun/generic-array-storage"
-license = "GPL-3.0 license"
+license = "MIT"
+license-file = "LICENCE"
 keywords = ["nalgebra", "typenum"]
 categories = ["no-std", "no-std::no-alloc"]
 exclude = [".github", ".gitignore"]