Update util scripts to use Ruby versions in .travis.yml

[ci skip]

script/SUPPORTED_VERSIONS

@@ -1 +0,0 @@
-2.4.1 2.3.5 2.2.7

script/install_gems_in_all_appraisals

@@ -1,6 +1,8 @@
 #!/bin/bash
 
-SUPPORTED_VERSIONS=$(<script/SUPPORTED_VERSIONS)
+set -euo pipefail
+
+SUPPORTED_VERSIONS=$(script/supported_ruby_versions)
 
 install-gems-for-version() {
   local version="$1"

script/run_all_tests

@@ -1,6 +1,8 @@
 #!/bin/bash
 
-SUPPORTED_VERSIONS=$(<script/SUPPORTED_VERSIONS)
+set -euo pipefail
+
+SUPPORTED_VERSIONS=$(script/supported_ruby_versions)
 
 run-tests-for-version() {
   local version="$1"

script/supported_ruby_versions

@@ -0,0 +1,7 @@
+#!/usr/bin/env ruby
+
+require 'yaml'
+
+travis_config_path = File.expand_path('../../.travis.yml', __FILE__)
+travis_config = YAML.load_file(travis_config_path)
+puts travis_config.fetch('rvm').join(' ')

script/update_gem_in_all_appraisals

@@ -1,6 +1,8 @@
 #!/bin/bash
 
-SUPPORTED_VERSIONS=$(<script/SUPPORTED_VERSIONS)
+set -euo pipefail
+
+SUPPORTED_VERSIONS=$(script/supported_ruby_versions)
 gem="$1"
 
 update-gem-for-version() {

script/update_gems_in_all_appraisals

@@ -1,6 +1,8 @@
 #!/bin/bash
 
-SUPPORTED_VERSIONS=$(<script/SUPPORTED_VERSIONS)
+set -euo pipefail
+
+SUPPORTED_VERSIONS=$(script/supported_ruby_versions)
 
 update-gems-for-version() {
   local version="$1"