test: Appveyor configuration (#1000)

This enables Windows-based CI testing

appveyor.yml

@@ -0,0 +1,31 @@
+# appveyor.yml
+init: 
+- ps: iex ((new-object net.webclient).DownloadString('https://raw.githubusercontent.com/appveyor/ci/master/scripts/enable-rdp.ps1'))
+- ps: Add-Content "c:\program files\postgresql\9.6\data\postgresql.conf" "wal_level=logical"
+- ps: Add-Content "c:\program files\postgresql\9.6\data\postgresql.conf" "max_wal_senders=3"
+- ps: Add-Content "c:\program files\postgresql\9.6\data\postgresql.conf" "wal_keep_segments=10"
+- ps: Add-Content "c:\program files\postgresql\9.6\data\postgresql.conf" "wal_sender_timeout=5s"
+- ps: Add-Content "c:\program files\postgresql\9.6\data\postgresql.conf" "max_replication_slots=10"
+- ps: Add-Content "c:\program files\postgresql\9.6\data\pg_hba.conf" "host    replication     all             127.0.0.1/32            trust"
+
+services: 
+  - postgresql96
+
+before_build:
+  - SET PATH=C:\Program Files\PostgreSQL\9.6\bin\;%PATH% 
+  - SET PGUSER=postgres 
+  - SET PGPASSWORD=Password12! 
+  - createuser -U postgres test
+  - psql -U postgres -c "alter user test with password 'test'" postgres 
+  - createdb -U postgres -O test test
+
+build_script:
+  - mvn clean package -DskipTests
+
+test_script:
+  - echo redirect escape ^> foo.bar
+  - echo privilegedPassword=Password12!>c:\projects\pgjdbc\build.local.properties
+  - mvn package
+
+cache:
+  - C:\Users\appveyor\.m2