XY Grid offsets don't include margin or padding

[steelwolf]

How can this bug be reproduced?
https://codepen.io/anon/pen/LzOorZ

What did you expect to happen?
Adding an offset in a grid-margin-x div should include the additional margin space.

What happened instead?
The offset occurs but since there isn't the additional margin space from a normal cell, the two columns do not align with each other.

Please List the Following:

• OS & version: OS X Sierra
• Node version (node -v) [Node v4+ is required] :
• FoundationPress version (see line 3 in package.json): 2.10.3
• Foundation version (see dependencies in package.json) : 6.4.1

From what I can tell in my testing, the issue occurs in _position.scss:
.grid-margin-x > .small-offset-1 {
margin-left: calc(8.33333% + 0.625rem);
}

Should be:
.grid-margin-x > .small-offset-1 {
margin-left: calc(8.33333% + 0.9375rem);
}

[colin-marshall]

@steelwolf I'm closing this because this is a Foundation issue, not a FoundationPress issue. If you feel I've done this in error, feel free to reopen.