CONTRIBUTING: updated for current project structure

These predated the move to Heptapod, having a few outdated parts.
Sending patches to Google Groups is not deprecated.

Less personal style in general.
18 jobs for branch/default in 3 minutes and 11 seconds
Status Job ID Name Coverage
  Current
passed #75011
tests-py2-hg-5.4

00:01:11

passed #75012
tests-py3-hg-5.4

00:00:48

 
  Compat
passed #75025
tests-py2-hg-4.3

00:00:41

passed #75024
tests-py2-hg-4.4

00:01:08

passed #75023
tests-py2-hg-4.5

00:01:10

passed #75022
tests-py2-hg-4.6

00:01:11

passed #75021
tests-py2-hg-4.7

00:00:54

passed #75020
tests-py2-hg-4.8

00:01:05

passed #75019
tests-py2-hg-4.9

00:01:09

passed #75018
tests-py2-hg-5.0

00:01:01

passed #75017
tests-py2-hg-5.1

00:01:21

passed #75016
tests-py2-hg-5.2

00:00:41

passed #75015
tests-py2-hg-5.3

00:01:08

failed #75013
allowed to fail
tests-py2-hg-default

00:01:36

passed #75014
tests-py2-hg-stable

00:01:01

passed #75028
tests-py3-hg-5.3

00:00:27

failed #75026
allowed to fail
tests-py3-hg-default

00:00:58

passed #75027
tests-py3-hg-stable

00:00:56

 
Name Stage Failure
failed
tests-py3-hg-default Compat
Skipped test-hg-author.t: missing feature: dulwich
Skipped test-illegal-contents.t: missing feature: git client (with ext::sh support) version < 2.24
Skipped test-pull.t: missing feature: dulwich
Skipped test-renames.t: missing feature: dulwich
Failed test-incoming.t: output changed
# Ran 33 tests, 8 skipped, 1 failed.
python hash seed: 369281581
# Cleaning up HGTMP /tmp/hgtests.4zijzg0j
ERROR: Job failed: exit code 1
failed
tests-py2-hg-default Compat
# Ret was: 0 (test-subrepos.t) 

Skipped test-git-gpg.t: missing feature: gpg client
Skipped test-illegal-contents.t: missing feature: git client (with ext::sh support) version < 2.24
Failed test-incoming.t: output changed
# Ran 39 tests, 2 skipped, 1 failed.
python hash seed: 1913811205
# Cleaning up HGTMP /tmp/hgtests.tOeJG3
ERROR: Job failed: exit code 1