Add support for numpydoc return value names (#2031)

Numpydoc specification allows for optional return value name in the form
of:
```
Returns
-------
name : type
    Some description
```
These were not being honored by the current regex for return lines. This
adds an optional, non-capturing group to the regex which accounts for
the `name : ` bit.

Fixes #2030

3 files changed, 9 insertions, 2 deletions

diff --git a/CONTRIBUTORS.txt b/CONTRIBUTORS.txt
index 40f0deb42..1ba25c7b4 100644
--- a/CONTRIBUTORS.txt
+++ b/CONTRIBUTORS.txt
@@ -162,3 +162,5 @@ Order doesn't matter (not that much, at least ;)
 * Tobias Hernstig: contributor
 
 * Jason Owen: contributor
+
+* Mitchell Young: minor adjustment to docparams
diff --git a/ChangeLog b/ChangeLog
index d372b303d..e53e250cf 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -12,6 +12,10 @@ Release date: |TBA|
 
       Close #1867
 
+   * Add support for nupmydoc optional return value names.
+
+      Close #2030
+
 
 What's New in Pylint 1.9.3?
 ===========================
diff --git a/pylint/extensions/_check_docs_utils.py b/pylint/extensions/_check_docs_utils.py
index a995e15e2..594bd860e 100644
--- a/pylint/extensions/_check_docs_utils.py
+++ b/pylint/extensions/_check_docs_utils.py
@@ -694,8 +694,9 @@ class NumpyDocstring(GoogleDocstring):
     )
 
     re_returns_line = re.compile(r"""
-        \s* ({type})$ # type declaration
-        \s* (.*)                       # optional description
+        \s* (?:\w+\s+:\s+)? # optional name
+        ({type})$                         # type declaration
+        \s* (.*)                          # optional description
     """.format(
         type=GoogleDocstring.re_multiple_type,
     ), re.X | re.S | re.M)