Add adaptive sparse polynomial chaos

[timueh]

see this paper and the section on it in the UQLab manual.

[timueh]

Hi @maqsoodmubarak,

good to hear that you are making progress. When you want to push your code, do the following:

1. Switch to (the branch prep-v0.1.3)[https://github.com/timueh/PolyChaos.jl/tree/prep-v0.1.3]
2. From this branch, create a new branch that you can call whatever.
3. Commit to this new branch.

The important things is to branch off the branch prep-v0.1.3

That makes sure we don't break anything.

I find this to be a helpful tutorial.

[maqsoodrajput]

Hey Till,

Now code for Sparse basis is working with new definitions of polynomials. I have also added a test file.
It is in new branch "sparseBasis"