Update CHANGELOG and setup.py

Author: tleonhardt

CHANGELOG.md

@@ -5,6 +5,7 @@
     * Added function to truncate a single line to fit within a given display width. `cmd2.utils.truncate_line`
     supports characters with display widths greater than 1 and ANSI style sequences.
     * Added line truncation support to `cmd2.utils` text alignment functions.
+    * Added support for Python 3.9 alpha
 
 ## 0.9.23 (January 9, 2020)
 * Bug Fixes

Pipfile

@@ -7,6 +7,7 @@ verify_ssl = true
 attrs = ">=16.3.0"
 colorama = ">=0.3.7"
 pyperclip = ">=1.6"
+setuptools = ">=34.4"
 wcwidth = ">=0.1.7"
 
 [dev-packages]

setup.py

@@ -25,6 +25,7 @@
 Programming Language :: Python :: 3.6
 Programming Language :: Python :: 3.7
 Programming Language :: Python :: 3.8
+Programming Language :: Python :: 3.9
 Programming Language :: Python :: Implementation :: CPython
 Topic :: Software Development :: Libraries :: Python Modules
 """.splitlines())))  # noqa: E128