Add CHANGELOG and better categories to cabal file

Also update appveyor.yml

appveyor.yml

@@ -11,8 +11,14 @@ environment:
 
 test: off
 
+skip_non_tags: true
+
 skip_branch_with_pr: true
 
+branches:
+  only:
+    - master
+
 install:
 - set PATH=C:\Program Files\PostgreSQL\9.6\bin\;%PATH%
 - curl -sS -ostack.zip -L --insecure http://www.stackage.org/stack/windows-x86_64

postgrest.cabal

@@ -10,7 +10,8 @@ author:                Joe Nelson, Adam Baker
 homepage:              https://postgrest.org
 maintainer:            Steve Chávez <stevechavezast@gmail.com>
 bug-reports:           https://github.com/PostgREST/postgrest/issues
-category:              Web
+category:              Executable, PostgreSQL, Network APIs
+extra-source-files:    CHANGELOG.md
 build-type:            Simple
 cabal-version:         >=1.10
 source-repository head