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/knapsack-0-1.py

@@ -1,38 +0,0 @@
-import unittest
-from math import floor
-
-
-def knapify(xs, capacity=None):
-    assert capacity is not None
-    n = len(xs)
-    # For 0/1 Knapsack, we must use a table, since this will encode which values
-    # work for which items. This is cleaner than including a separate data
-    # structure to capture it.
-    maxes = [[0 for x in range(capacity + 1)] for x in range(n + 1)]
-
-    # Build table maxes[][] in bottom up manner
-    for row in range(n + 1):
-        for col in range(capacity + 1):
-            if row == 0 or col == 0:
-                maxes[row][col] = 0
-            elif xs[row - 1][0] <= col:
-                maxes[row][col] = max(
-                    xs[row - 1][1] + maxes[row - 1][col - xs[row - 1][0]],
-                    maxes[row - 1][col])
-            else:
-                maxes[row][col] = maxes[row - 1][col]
-
-    return maxes[-1][capacity]
-
-
-################################################################################
-# Tests
-################################################################################
-class Test(unittest.TestCase):
-    def test_one_cake(self):
-        actual = knapify([(3, 10), (2, 15), (7, 2), (12, 20)], capacity=12)
-        expected = None
-        self.assertEqual(actual, expected)
-
-
-unittest.main(verbosity=2)