Path to license files cause a problem on Windows filesystem.

Hello. I added this package as a dependency of my project and executed cargo build, which threw an error below:

PS> cargo build                                                                                                 
  Downloaded unicode-ident v1.0.12
  Downloaded quote v1.0.35
  Downloaded syn v1.0.109
  Downloaded gfxmath-vec3 v0.1.4
error: failed to download replaced source registry `crates-io`

Caused by:
  failed to unpack package `gfxmath-vec3 v0.1.4`

Caused by:
  failed to unpack entry at `gfxmath-vec3-0.1.4/license/LICENSE`

Caused by:
  failed to unpack `C:\Users\f2koi\.cargo\registry\src\index.crates.io-6f17d22bba15001f\gfxmath-vec3-0.1.4\license\LICENSE`

Caused by:
  failed to unpack `gfxmath-vec3-0.1.4/license/LICENSE` into `C:\Users\f2koi\.cargo\registry\src\index.crates.io-6f17d22bba15001f\gfxmath-vec3-0.1.4\license\LICENSE`

Caused by:
  The system cannot find the path specified. (os error 3)

I found out there's a file named LICENSE in the package root and Windows can't distinguish it from its lowercase form license. In turn cargo fails to unpack license\LICENSE because license\ is not a directory.

So the structure of this package needs to be reorganized to avoid path name clashes like that.

Thank you.