Bump release to alpha 20; update release notes for alpha 19.

docs/release_notes.rst

@@ -2,6 +2,14 @@
 Release Notes
 =============
 
+1.0 Alpha 19 HOTFIX
+-------------------
+
+*October 10, 2018*
+
+A hotfix relase was necessary to adjust settings for the source to build
+correctly on Read The Docs and Docker Hub, and to package correctly on PyPI.
+
 1.0 Alpha 18
 ------------
 

lakesuperior/__init__.py

@@ -4,7 +4,7 @@ from os import path
 
 
 version = '1.0 alpha'
-release = '1.0.0a19'
+release = '1.0.0a20'
 
 basedir = path.dirname(path.realpath(__file__))
 """