Let's just keep adding YAML until this works.

appveyor.yml

@@ -12,16 +12,27 @@ skip_commits:
 
 environment:
   Appveyor: true
-  MYSQL_ENV_MYSQL_USER: root
-  MYSQL_ENV_MYSQL_PASSWORD: Password12!
+  # Postgres
+  POSTGRES_PATH: C:\Program Files\PostgreSQL\9.4
   PGUSER: postgres
   PGPASSWORD: Password12!
+  POSTGRES_ENV_POSTGRES_USER: postgres
+  POSTGRES_ENV_POSTGRES_PASSWORD: Password12!
+  POSTGRES_ENV_POSTGRES_DB: test
+  # MySQL
+  MYSQL_PATH: C:\Program Files\MySql\MySQL Server 5.7
   MYSQL_PWD: Password12!
+  MYSQL_ENV_MYSQL_USER: root
+  MYSQL_ENV_MYSQL_PASSWORD: Password12!
+  MYSQL_ENV_MYSQL_DATABASE: test
 services:
 - mssql2016
 - mysql
 - postgresql
 
+init:
+  - SET PATH=%POSTGRES_PATH%\bin;%MYSQL_PATH%\bin;%PATH%
+
 nuget:
   disable_publish_on_pr: true