Fix widget footer margins

[cayb0rg]

Prevents widget footer from centering itself in the page.

[clpetersonucf]

This works, but I'd actually prefer to add margin: 0 auto; to the section.widget .center selector in the same file. Currently, the fix causes the player to left-align to the available space, while the alternative would center-align the player and footer together (but we should still test the player in various embed environments to make sure it displays properly).

[cayb0rg]

True. I considered that as well and thought being left-aligned looked more congruent with WebCourses, especially on wide screen sizes. If the author wanted to center one embedded in a page, they could use WebCourses' text centering option (or add style = "text-align: center;" if it's outside WebCourses). However, I'm totally open to making it centered by default since this centering option is not available for LTI embedded widgets, and there are ways of making it left-aligned again in pages if they wanted it to be.

Centering also does look better when opened in new tab.