Enable CI builds only for push and PRs to master.

.circleci/config.yml

@@ -212,6 +212,9 @@ jobs:
 workflows:
   version: 2
   build:
+    branches:
+      only:
+        - master
     jobs:
       #- cabal-ghc-8.6.5
       #- cabal-ghc-8.4.4

.github/workflows/haskell.yml

@@ -1,6 +1,10 @@
 name: Haskell CI
 
-on: [push, pull_request]
+on:
+  push:
+    branches:
+      - master
+  pull_request:
 
 jobs:
   build:

.travis.yml

@@ -2,6 +2,9 @@
 # You can use any of the options supported by packcheck as environment
 # variables here.  See https://github.com/harendra-kumar/packcheck for all
 # options and their explanation.
+
+if: branch = master
+
 # dist: trusty
 dist: xenial
 env:

appveyor.yml

@@ -2,6 +2,10 @@
 # You can use any of the options supported by packcheck as environment
 # variables here.  See https://github.com/harendra-kumar/packcheck for all
 # options and their explanation.
+branches:
+  only:
+    - master
+
 environment:
     # ------------------------------------------------------------------------
     # Global options, you can use these per build as well