.travis.yml: Simplify Travis CI.

* Remove CI functions for make test-all.
  I want to simplify the `.travis.yml` for us to maintain it easily. When we
  need to skip a test, we can fix the test file directly.
  I removed the `tool/ci_functions.sh` too. I confirmed the file is not used in
  any other files.
* .travis.yml: Remove a notification for IRC channel.
  GitHub Actions don't use this notification. The setting is outdated.
* Fix to skip the commit including the document keyword.
  There were 2 `if` syntax lines in the file.
* Remove ccache.

1 files changed, 0 insertions, 29 deletions

diff --git a/tool/ci_functions.sh b/tool/ci_functions.sh
deleted file mode 100644
index 7066bbe4ec..0000000000
--- a/tool/ci_functions.sh
+++ /dev/null
@@ -1,29 +0,0 @@
-# -*- BASH -*-
-# Manage functions used on a CI.
-# Run `. tool/ci_functions.sh` to use it.
-
-# Create options with patterns `-n !/name1/ -n !/name2/ ..` to exclude the test
-# method names by the method names `name1 name2 ..`.
-# See `ruby tool/test/runner.rb --help` `-n` option.
-function ci_to_excluded_test_opts {
-  local tests_str="${1}"
-  # Use the backward matching `!/name$/`, as the perfect matching doesn't work.
-  # https://bugs.ruby-lang.org/issues/16936
-  ruby <<EOF
-    opts = "${tests_str}".split.map { |test| "-n \!/#{test}\$$/" }
-    puts opts.join(' ')
-EOF
-  return 0
-}
-
-# Create options with patterns `-n name1 -n name2 ..` to include the test
-# method names by the method names `name1 name2 ..`.
-# See `ruby tool/test/runner.rb --help` `-n` option.
-function ci_to_included_test_opts {
-  local tests_str="${1}"
-  ruby <<EOF
-    opts = "${tests_str}".split.map { |test| "-n #{test}" }
-    puts opts.join(' ')
-EOF
-  return 0
-}