[WIP] Add Common Interface Bindings

[ChrisRackauckas]

This adds LSODA to the common interface. For example, as seen in the tests, problems on things like 2-dimensional matrix are supported through solve:

using LSODA, DiffEqProblemLibrary
prob = prob_ode_2Dlinear
sol = solve(prob,LSODAAlg(),save_timeseries=false,saveat=[1/2])

Additionally, this allows LSODA to be the backend solver for sensitivity analysis, parameter estimation, etc.

Currently there are some details to fix up:

• If the package is named LSODA, then the algorithm type cannot be named LSODA. This is a bummer. Currently I named it LSODAAlg. Is there a better name?
• Setup with save_timeseries. Currently you can only use the saveat style of saving instead of letting it save at each timepoint it steps to. Can someone help me find out how to get the value of each timestep @sdwfrost ?

[coveralls]

Coverage decreased (-0.6%) to 90.909% when pulling ec8e0d5 on ChrisRackauckas:common into 913574f on rveltz:master.

[coveralls]

Coverage decreased (-0.6%) to 90.909% when pulling ec8e0d5 on ChrisRackauckas:common into 913574f on rveltz:master.

[coveralls]

Coverage decreased (-0.6%) to 90.909% when pulling ec8e0d5 on ChrisRackauckas:common into 913574f on rveltz:master.

[rveltz]

Good work! Thank you for adding tests too.

[rveltz]

I am not sure why you need to put all this in LSODA.jl. You can just call LSODA from DifferentialEquations by, for example, putting common.jl in DifferentialEquations' sources?
.

[ChrisRackauckas]

This was still WIP, but the changes can be further PRs. @sdwfrost do you have a suggestion for saving each step? I assume that's just an option somewhere.

I am not sure why you need to put all this in LSODA.jl.

Well, it's a very short code. You can read the numerous discussions that have gone on about the ecosystem structure, but the key idea is that this allows one to use the common interface without requiring the full 40,000+ lines of code represented by the metapackage DiffererntialEquations.jl. This setup allows someone to try LSODA along with every other code, and if they find LSODA is good for their application, reduce the dependencies to only LSODA without having to change the code (to write to a different interface). In addition, having this package-wise instead of centralized allows for add-on packages to not require every solver. Therefore DiffEqParamEstim is now able to use LSODA as a backend in parameter estimation, without requiring any other packages. If you wish to know more, there's a whole trail of additional explanations for this setup, and similar setups in JuMP, JuliaML, Plots.jl, etc. already online.

[rveltz]

That makes sense, thank you.