updating neml submodule, fixes chaboche hardening and string parsing interface

[lynnmunday]

This is an incremental neml update from April 7, 2020 (commit a6b90955). This update includes:
-Fix for the Chaboche hardening
-Modification to the neml string parsing interface to take a model name.

This update is required for modifications made to the blackbear neml interface in ref #78.

ref #66

[lynnmunday]

@bwspenc I was updating the neml submodule. I wanted to see if I could. My other pr needs the updated string parser interface that this has.

[moosebuild]

Job Test on eeedcfa wanted to post the following:

View the site here

This comment will be updated on new commits.

[bwspenc]

Yes, if the submodule update doesn't break anything (which it appears it does not), you can definitely do that. Just one comment -- the message is kind of messy. What does 'This is an improvement' mean? This kind of looks like it is the result of squashing several commits, but not editing the resulting combined message. This isn't a huge deal, but it matters because everything that is in there shows up in the commit history. This is the text I'm talking about:

This neml update includes fixes for the chaboche hardening and modifies the string parsing interface to take a model name.
This is an improvement.
This is part of neml submodule maintenance

[lynnmunday]

Yes, if the submodule update doesn't break anything (which it appears it does not), you can definitely do that. Just one comment -- the message is kind of messy. What does 'This is an improvement' mean? This kind of looks like it is the result of squashing several commits, but not editing the resulting combined message. This isn't a huge deal, but it matters because everything that is in there shows up in the commit history. This is the text I'm talking about:

This neml update includes fixes for the chaboche hardening and modifies the string parsing interface to take a model name.
This is an improvement.
This is part of neml submodule maintenance

I edited the PR comment. I thought only the git message showed up in the commit history but that is messy too.

[bwspenc]

Well, I actually already merged it. It's not a huge deal -- I brought that up mostly for future reference.

[bwspenc]

The revised version does look nice though! I'm pretty sure it won't show up in the commit history since it was already merged.