Builds list on commit details page loads slowly

[kostmo]

Example commit details page:
https://dr.pytorch.org/commit-details.html?sha1=f3f372edc0981e2a85c18df0ae91bd4f60dfff44

This page uses the same underlying VIEW, "best_pattern_match_augmented_builds", as the build details page (see issue #49).

However, for reasons not yet discovered, the same query optimization method does not work between both uses of the view (querying by commit vs querying by build number).

[kostmo]

The following API endpoint now has improved performance:
https://dr.pytorch.org/api/commit-builds?sha1=f3f372edc0981e2a85c18df0ae91bd4f60dfff44

Version	Time
Original	17.8 sec
After best_pattern_match_augmented_builds view simplification (397efa1)	8.5 sec
After manual predicate pushing (b57d574)	1.9 sec

cc @ezyang, @dskhudia