added info interface, updated simulators to use it (sisl/DeepRL.jl#5)

[zsunberg]

Here's how I think the information interface should look.

There are four functions in src/model/info.jl. Problem writers and solver writers can implement them if they want to provide more information.

I also updated HistoryRecorder and stepthrough to use these functions.

I think action_info will be really useful for my online tree-based solvers because it will make it easier to save the trees for later examination.

Any thoughts @rejuvyesh and @MaximeBouton ?

[coveralls]

Coverage increased (+1.1%) to 77.273% when pulling df62b44 on info into dfb351c on master.

[MaximeBouton]

I think the info interface is consistent with the rest of the package. I will try to use it on sample problems and give some user feedback.

One concern is should it stay in POMDPToolbox or go in POMDPs ?
The definition of generate_sr and generate_sor are in POMDPs.

[coveralls]

Coverage increased (+1.2%) to 77.378% when pulling 74d11e8 on info into d776c60 on master.

[zsunberg]

@MaximeBouton the reason to put it in POMDPToolbox is because it is peripheral and might be a distraction in the documentation of the core interface. I've generally been more happy putting things in POMDPToolbox than in POMDPs. If it becomes really important in the future, we can move it to POMDPs.

[coveralls]

Coverage increased (+1.2%) to 77.378% when pulling eb6ff8d on info into d776c60 on master.

[coveralls]

Changes Unknown when pulling bcdb0e8 on info into ** on master**.

[zsunberg]

Hey @rejuvyesh , could you take a quick look at this and give it a thumbs up if you think it looks good? I'm about to merge it, but want to catch any problems you might see. Thanks!!

[rejuvyesh]

LGTM! Not sure we need to specify it's a Dict although it looks like it's only a suggestion.