Splice ./universe directory into ./

Manually merging:
- README.md: I added the description from universe/README.md into the heading of
  dotfiles/README.md.
- .envrc: dotfiles/.envrc was a superset of universe/.envrc
- .gitignore: Adding some of the ignored patterns from universe/.gitignore to
  dotfiles/.gitignore

Everything else here should be a simple rename.

universe/data_structures_and_algorithms/inflight-entertainment.py

@@ -1,35 +0,0 @@
-# possible :: Int -> [Int] -> Bool
-def possible(flight_duration, film_durations):
-    seeking = set()
-
-    for x in film_durations:
-        if x in seeking:
-            return True
-        else:
-            seeking.add(flight_duration - x)
-
-    return False
-
-
-should = [
-    (10, [1, 9, 8, 8, 8]),
-    (10, [1, 9]),
-    (10, [1, 9, 5, 5, 6]),
-    (1, [0.5, 0.5]),
-    (1, [0.5, 0.5]),
-]
-
-for a, b in should:
-    print("Testing: %s %s" % (a, b))
-    assert possible(a, b)
-
-shouldnt = [
-    (10, [1, 10, 1, 2, 1, 12]),
-    (1, [0.25, 0.25, 0.25, 0.25]),
-    (5, [1, 2, 2]),
-]
-for a, b in shouldnt:
-    print("Testing: %s %s" % (a, b))
-    assert not possible(a, b)
-
-print("Tests pass")