Include the sm breakpoint in the margin-bottom reset
Include the sm breakpoint in the margin-bottom reset

for the Add Group and Add Actor forms

Before:
https://user-images.githubusercontent.com/1863540/51654726-19aa1d80-1f4e-11e9-83ad-e0aa1f3f91f3.png

After:
https://user-images.githubusercontent.com/1863540/51654753-2f1f4780-1f4e-11e9-9015-0bc0adf9f14f.png

jnunemaker/flipper,jnunemaker/flipper,jnunemaker/flipper,jnunemaker/flipper