lint: Replace (most of) pycodestyle with Black.

Signed-off-by: Anders Kaseorg <anders@zulip.com>

setup.cfg

@@ -2,74 +2,26 @@
 ignore =
     # Each of these rules are ignored for the explained reason.
 
-    # "whitespace before ':'"
-    # Black disagrees with this.
-    E203,
-
-    # "multiple spaces before operator"
-    # There are several typos here, but also several instances that are
-    # being used for alignment in dict keys/values using the `dict`
-    # constructor. We could fix the alignment cases by switching to the `{}`
-    # constructor, but it makes fixing this rule a little less
-    # straightforward.
-    E221,
-
-    # 'missing whitespace around arithmetic operator'
-    # This should possibly be cleaned up, though changing some of
-    # these may make the code less readable.
-    E226,
-
-    # New rules in pycodestyle 2.4.0 that we haven't decided whether to comply with yet
-    E252, W504,
-
-    # "multiple spaces after ':'"
-    # This is the `{}` analogue of E221, and these are similarly being used
-    # for alignment.
-    E241,
-
-    # "unexpected spaces around keyword / parameter equals"
-    # Many of these should be fixed, but many are also being used for
-    # alignment/making the code easier to read.
-    E251,
-
-    # "block comment should start with '#'"
-    # These serve to show which lines should be changed in files customized
-    # by the user. We could probably resolve one of E265 or E266 by
-    # standardizing on a single style for lines that the user might want to
-    # change.
-    E265,
-
-    # "too many leading '#' for block comment"
-    # Most of these are there for valid reasons.
-    E266,
-
-    # "expected 2 blank lines after class or function definition"
-    # Zulip only uses 1 blank line after class/function
-    # definitions; the PEP-8 recommendation results in super sparse code.
-    E302, E305,
+    # All formatting is handled by Black.
+    E1,
+    E2,
+    E3,
+    E401,
+    E5,
+    E701,
+    E702,
+    E703,
+    E704,
+    W1,
+    W2,
+    W3,
+    W5,
 
     # "module level import not at top of file"
     # Most of these are there for valid reasons, though there might be a
     # few that could be eliminated.
     E402,
 
-    # "line too long"
-    # Zulip is a bit less strict about line length, and has its
-    # own check for this (see max_length)
-    E501,
-
     # "do not assign a lambda expression, use a def"
     # Fixing these would probably reduce readability in most cases.
     E731,
-
-    # "line break before binary operator"
-    # This is a bug in the `pep8`/`pycodestyle` tool -- it's completely backward.
-    # See https://github.com/PyCQA/pycodestyle/issues/498 .
-    W503,
-
-    # This number will probably be used for the corrected, inverse version of
-    # W503 when that's added: https://github.com/PyCQA/pycodestyle/pull/502
-    # Once that fix lands and we update to a version of pycodestyle that has it,
-    # we'll want the rule; but we might have to briefly ignore it while we fix
-    # existing code.
-    # W504,