rename FDM => FiniteDifferenceMethods

[StefanKarpinski]

No description provided.

[oxinabox]

@StefanKarpinski ok yes.

[KristofferC]

ERROR: failed to clone from https://github.com/invenia/FiniteDifferences.jl.git, error: GitError(Code:ERROR, Class:Net, unexpected HTTP status code: 404)

with the current URL.

Please try this out locally with the stuff depending on this package. I am getting

julia> using Nabla
[ Info: Precompiling Nabla [49c96f43-aa6d-5a04-a506-44c7070ebe78]
ERROR: LoadError: LoadError: ArgumentError: Package Nabla does not have FDM in its dependencies:
- If you have Nabla checked out for development and have
  added FDM as a dependency but haven't updated your primary
  environment's manifest file, try `Pkg.resolve()`.
- Otherwise you may need to report an issue with Nabla
Stacktrace:
 [1] require(::Module, ::Symbol) at ./loading.jl:836
 [2] include at ./boot.jl:326 [inlined]
 [3] include_relative(::Module, ::String) at ./loading.jl:1038
 [4] include at ./sysimg.jl:29 [inlined]
 [5] include(::String) at /Users/kristoffer/.julia/packages/Nabla/D60dX/src/Nabla.jl:3
 [6] top-level scope at none:0

after add Nabla using this branch.

[oxinabox]

Suggested change

	repo = "https://github.com/invenia/FiniteDifferences.jl.git"
	repo = "https://github.com/JuliaDiff/FiniteDifferences.jl.git"