Include an author list in the documentation

The standard "author" variable is only used by default in some output
formats, like EPUB.

Authors are generated automatically from git history, with a .mailmap
file used to normalize commits from people's various usernames and email
addresses.

.mailmap

@@ -0,0 +1,22 @@
+Alli Black <black.alli@gmail.com>
+Barney Potter <barney.potter.24@gmail.com>
+Emma Hodcroft <emmahodcroft@gmail.com>
+Emma Hodcroft <freezefire666@yahoo.com>
+Gytis Dudas <gytisdudas@gmail.com>
+James Hadfield <jameshadfield@users.noreply.github.com>
+James Hadfield <jh22@sanger.ac.uk>
+James Hadfield <jh22@sanger.ac.uk>
+John Huddleston <huddlej@gmail.com>
+Louise Moncla <lhmoncla@gmail.com>
+Richard Neher <neher@login10.cluster.bc2.ch>
+Richard Neher <neher@login11.cluster.bc2.ch>
+Richard Neher <neher@login20.cluster.bc2.ch>
+Richard Neher <richard.neher@tuebingen.mpg.de>
+Richard Neher <richard.neher@tuebingen.mpg.de>
+Richard Neher <richard.neher@unibas.ch>
+Sarah Murata <sarah.d.murata@gmail.com>
+Sidney Bell <sidneymb@uw.edu>
+Sidney Bell <sidneymbell@users.noreply.github.com>
+Thomas Sibley <tsibley@fredhutch.org>
+Trevor Bedford <trevor@bedford.io>
+Trevor Bedford <trvrb@trevorbedford.com>

docs/authors.rst

@@ -0,0 +1,4 @@
+Authors
+=======
+
+Augur includes contributions from |authors|.

docs/conf.py

@@ -18,10 +18,34 @@
 # -- Project information -----------------------------------------------------
 
 from datetime import date
+import subprocess
+
+def git_authors():
+    result = subprocess.run(
+        ["git", "shortlog", "--summary"],
+        stdout = subprocess.PIPE,
+        check  = True)
+
+    names = [
+        line.strip().split("\t")[1]
+            for line in result.stdout.decode("utf-8").splitlines()
+    ]
+
+    return names
+
+def prose_list(items):
+    if not items:
+        return ""
+    if len(items) == 1:
+        return items[0]
+    elif len(items) == 2:
+        return " and ".join(items)
+    else:
+        return ", ".join([*items[0:-1], "and " + items[-1]])
 
 project = 'augur'
 copyright = '2014–%d Trevor Bedford and Richard Neher' % (date.today().year)
-author = 'James Hadfield, John Huddleston, Emma Hodcroft, Tom Sibley, Barney Potter, Trevor Bedford, Richard Neher'
+author = prose_list(git_authors())
 
 
 # -- General configuration ---------------------------------------------------
@@ -39,6 +63,13 @@
 # This pattern also affects html_static_path and html_extra_path.
 exclude_patterns = ['_build', 'Thumbs.db', '.DS_Store']
 
+# A string of reStructuredText that will be included at the end of every source
+# file that is read. This is a possible place to add substitutions that should
+# be available in every file.
+rst_epilog = f"""
+.. |authors| replace:: {author}
+"""
+
 
 # -- Options for HTML output -------------------------------------------------
 

docs/index.rst

@@ -16,6 +16,7 @@ Welcome to augur's documentation!
    tutorials
    commands
    APIdoc
+   authors