whatsnew: Move 1.9 development series to 2.0

doc/source/whatsnew/1.9.rst → doc/source/whatsnew/2.0.rst

-What's New In python-apt 1.9
+What's New In python-apt 2.0
 ============================
-This is a development series, and there will be more API changes in point
-releases.
+Changes since 1.8.
 
 Added
 -----

po/python-apt.pot

@@ -8,7 +8,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: PACKAGE VERSION\n"
 "Report-Msgid-Bugs-To: \n"
-"POT-Creation-Date: 2020-01-20 10:17+0100\n"
+"POT-Creation-Date: 2020-04-09 09:07+0200\n"
 "PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
 "Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
 "Language-Team: LANGUAGE <LL@li.org>\n"