Revert check for open_sans option name in spine_get_option

This "trueish" logic is already performed by default for any
option that is requested via spine_get_option()
Use spine_get_option() for open_sans check when enqueueing

We can use `true` without quotes here, as we're doing a loose
comparison to the value returned by spine_get_option()
Remove unneeded else statement
Re-add code reverted in 2737609f4 around builder templates
Merge pull request #30 from washingtonstateuniversity/fix/functions

[PR] Update for spine_get_option( 'open_sans' )