Backport some items from master in RELEASING.txt

Steve Piercy

2018-04-26 b2475f2ffbab6086e365a37e8b8cb4a857b26f47

Backport some items from master in RELEASING.txt

 RELEASING.txt

@@ -139,13 +139,15 @@

- Edit `https://en.wikipedia.org/wiki/Pylons_project <https://en.wikipedia.org/wiki/Pylons_project>`_.

- Edit `https://en.wikipedia.org/wiki/Comparison_of_web_frameworks <https://en.wikipedia.org/wiki/Comparison_of_web_frameworks>`_.

- Announce to Twitter.

```
Pyramid 1.x released.

PyPI
https://pypi.python.org/pypi/pyramid/1.x
https://pypi.org/project/pyramid/1.x/

=== One time only for new version, first pre-release ===
What's New
@@ -163,9 +165,8 @@
```
Pyramid 1.X.X has been released.

Here are the changes:

<<changes>>
The full changelog is here:
https://docs.pylonsproject.org/projects/pyramid/en/1.X-branch/changes.html

What's New In Pyramid 1.X:
https://docs.pylonsproject.org/projects/pyramid/en/1.X-branch/whatsnew-1.X.html