travis: disable for pull requests

travis is too slow for us and confuse contributors, who think they have
to get travis tests green.
We have now pr bots instead.

.travis.yml

@@ -1,35 +0,0 @@
-language: nix
-sudo: true
-# 'sudo: false' == containers that start fast, but only get 4G ram;
-# 'sudo: true'  == VMs that start slow, but with 8G
-# ..as per:  https://docs.travis-ci.com/user/ci-environment/#Virtualization-environments
-# Nixpkgs PR tests OOM with 4G: https://github.com/NixOS/nixpkgs/issues/24200
-
-matrix:
-    include:
-        - os: linux
-          sudo: required
-          script:
-              - ./maintainers/scripts/travis-nox-review-pr.sh nixpkgs-verify nixpkgs-manual nixpkgs-tarball nixpkgs-unstable
-              - ./maintainers/scripts/travis-nox-review-pr.sh nixos-options nixos-manual
-          env:
-            - BUILD_TYPE="Test Nixpkgs evaluation & NixOS manual build"
-        - os: linux
-          sudo: required
-          dist: trusty
-          before_script:
-              - sudo mount -o remount,exec,size=2G,mode=755 /run/user
-          script: ./maintainers/scripts/travis-nox-review-pr.sh nox pr
-          env:
-            - BUILD_TYPE="Build affected packages (Linux)"
-        - os: osx
-          osx_image: xcode7.3
-          script: ./maintainers/scripts/travis-nox-review-pr.sh nox pr
-          env:
-            - BUILD_TYPE="Build affected packages (macOS)"
-env:
-    global:
-        - GITHUB_TOKEN=5edaaf1017f691ed34e7f80878f8f5fbd071603f
-
-notifications:
-    email: false

maintainers/scripts/travis-nox-review-pr.sh

@@ -1,82 +0,0 @@
-#! /usr/bin/env bash
-set -e
-
-while test -n "$1"; do
-
-    # tell Travis to use folding
-    echo -en "travis_fold:start:$1\r"
-
-    case $1 in
-
-        nixpkgs-verify)
-            echo "=== Verifying that nixpkgs evaluates..."
-
-            nix-env --file $TRAVIS_BUILD_DIR --query --available --json > /dev/null
-            ;;
-
-        nixos-options)
-            echo "=== Checking NixOS options"
-
-            nix-build $TRAVIS_BUILD_DIR/nixos/release.nix --attr options --show-trace
-            ;;
-
-        nixos-manual)
-            echo "=== Checking NixOS manuals"
-
-            nix-build $TRAVIS_BUILD_DIR/nixos/release.nix --attr manual --show-trace
-            ;;
-
-        nixpkgs-manual)
-            echo "=== Checking nixpkgs manuals"
-
-            nix-build $TRAVIS_BUILD_DIR/pkgs/top-level/release.nix --attr manual --show-trace
-            ;;
-
-        nixpkgs-tarball)
-            echo "=== Checking nixpkgs tarball creation"
-
-            nix-build $TRAVIS_BUILD_DIR/pkgs/top-level/release.nix --attr tarball --show-trace
-            ;;
-
-        nixpkgs-unstable)
-            echo "=== Checking nixpkgs unstable job"
-
-            nix-instantiate $TRAVIS_BUILD_DIR/pkgs/top-level/release.nix --attr unstable --show-trace
-            ;;
-
-        nixpkgs-lint)
-            echo "=== Checking nixpkgs lint"
-
-            nix-shell --packages nixpkgs-lint --run "nixpkgs-lint -f $TRAVIS_BUILD_DIR"
-            ;;
-
-        nox)
-            echo "=== Fetching Nox from binary cache"
-
-            # build nox (+ a basic nix-shell env) silently so it's not in the log
-            nix-shell -p nox stdenv --command true
-            ;;
-
-        pr)
-            if [ "$TRAVIS_PULL_REQUEST" == "false" ]; then
-                echo "=== No pull request found"
-            else
-                echo "=== Building pull request #$TRAVIS_PULL_REQUEST"
-
-                token=""
-                if [ -n "$GITHUB_TOKEN" ]; then
-                    token="--token $GITHUB_TOKEN"
-                fi
-
-                nix-shell --packages nox --run "nox-review pr --slug $TRAVIS_REPO_SLUG $token $TRAVIS_PULL_REQUEST"
-            fi
-            ;;
-
-        *)
-            echo "Skipping unknown option $1"
-            ;;
-    esac
-
-    echo -en "travis_fold:end:$1\r"
-    shift
-done