WIP : Forward Euler implementation using HHL

[dgan181]

First implementation of the Forward Euler method using the existing HHL implementation.
(https://arxiv.org/abs/1010.2745).

[GiggleLiu]

Super cool!
About your issues

1. When I try to run the test file, I am given an error saying that the functions haven't been defined. I have to run the file (src\lin_diffEq_HHL.jl) separately to get the test file to execute.

After excuting git merge master, I can run test/lin_diffEq_HHL.jl correctly.
Your issue may be related to using an older version master branch with an incorrect Project.toml. Try to merge the master branch first (sometimes, you need to reinstall related packages).

Also, the dependacy of OrdinaryDiffEq should be added to Project.toml. Otherwise the CI will fail. Is it possible to not using this package in Test? If it is nessesary, please add it in Project.toml by excuting the following commands in pkg mode in the top level folder

pkg> activate .
(QuAlgorithmZoo) pkg> add OrdinaryDiffEq

2. I am not sure how to input the input state as given in the paper. (Coupled to the states that represent time)

(reading the paper, I will be back soon...)

[Roger-luo]

The older UUID was not compatible with METADATA. I've fixed it in a recent commit.

If you want to use a package in test only, you should put it into [extra] and [target]. This will let the Pkg know this is test only dependency.

[dgan181]

@GiggleLiu I made the changes you asked me make. I still get the same error.

[Roger-luo]

I think the Project.toml configuration is fixed now. This is due to legacy configuration generated in 0.6 era. I've updated it to 1.0 version. 0.7 is dropped.

@dgan181 please notice that as the README says, this repo is currently a bit messy (its code base etc.) also the examples are all should be working, the interface might be a bit ugly. So feel free to tell us if there's anything you think can be improved during your own development.