Use goal cards on user profile page
Add conditional post and affirmation form rendering

If the user has not yet affirmed the goal, then he can not post. If the
user has already affirmed or has created the goal, he can not affirm.
Consolidate `.inner`

There was no need for `.nav-inner` and `.body-inner`. Rather than
nesting everything under a single `.inner` the header and body are split
to allow for a full width header
Move `nav` style to `_header.css.scss`
Add basic header styles
Goal card should show affirmers rather than critical mass
Add progress bar to `goal/show`
Don't render affirmations list if none exist
Fix post gating logic

User can post if he has affirmed the goal or is the owner