Removed Kokoro configs for old Ruby versions.
diff --git a/kokoro/linux/ruby23/build.sh b/kokoro/linux/ruby23/build.sh
deleted file mode 100755
index 503a320..0000000
--- a/kokoro/linux/ruby23/build.sh
+++ /dev/null
@@ -1,18 +0,0 @@
-#!/bin/bash
-#
-# This is the top-level script we give to Kokoro as the entry point for
-# running the "pull request" project:
-#
-# This script selects a specific Dockerfile (for building a Docker image) and
-# a script to run inside that image. Then we delegate to the general
-# build_and_run_docker.sh script.
-
-# Change to repo root
-cd $(dirname $0)/../../..
-
-export DOCKERHUB_ORGANIZATION=protobuftesting
-export DOCKERFILE_DIR=kokoro/linux/dockerfile/test/ruby
-export DOCKER_RUN_SCRIPT=kokoro/linux/pull_request_in_docker.sh
-export OUTPUT_DIR=testoutput
-export TEST_SET="ruby23"
-./kokoro/linux/build_and_run_docker.sh
diff --git a/kokoro/linux/ruby23/continuous.cfg b/kokoro/linux/ruby23/continuous.cfg
deleted file mode 100644
index f5c6498..0000000
--- a/kokoro/linux/ruby23/continuous.cfg
+++ /dev/null
@@ -1,11 +0,0 @@
-# Config file for running tests in Kokoro
-
-# Location of the build script in repository
-build_file: "protobuf/kokoro/linux/ruby23/build.sh"
-timeout_mins: 120
-
-action {
- define_artifacts {
- regex: "**/sponge_log.xml"
- }
-}
diff --git a/kokoro/linux/ruby23/presubmit.cfg b/kokoro/linux/ruby23/presubmit.cfg
deleted file mode 100644
index f5c6498..0000000
--- a/kokoro/linux/ruby23/presubmit.cfg
+++ /dev/null
@@ -1,11 +0,0 @@
-# Config file for running tests in Kokoro
-
-# Location of the build script in repository
-build_file: "protobuf/kokoro/linux/ruby23/build.sh"
-timeout_mins: 120
-
-action {
- define_artifacts {
- regex: "**/sponge_log.xml"
- }
-}
diff --git a/kokoro/linux/ruby24/build.sh b/kokoro/linux/ruby24/build.sh
deleted file mode 100755
index 68585aa..0000000
--- a/kokoro/linux/ruby24/build.sh
+++ /dev/null
@@ -1,18 +0,0 @@
-#!/bin/bash
-#
-# This is the top-level script we give to Kokoro as the entry point for
-# running the "pull request" project:
-#
-# This script selects a specific Dockerfile (for building a Docker image) and
-# a script to run inside that image. Then we delegate to the general
-# build_and_run_docker.sh script.
-
-# Change to repo root
-cd $(dirname $0)/../../..
-
-export DOCKERHUB_ORGANIZATION=protobuftesting
-export DOCKERFILE_DIR=kokoro/linux/dockerfile/test/ruby
-export DOCKER_RUN_SCRIPT=kokoro/linux/pull_request_in_docker.sh
-export OUTPUT_DIR=testoutput
-export TEST_SET="ruby24"
-./kokoro/linux/build_and_run_docker.sh
diff --git a/kokoro/linux/ruby24/continuous.cfg b/kokoro/linux/ruby24/continuous.cfg
deleted file mode 100644
index a1ccfc0..0000000
--- a/kokoro/linux/ruby24/continuous.cfg
+++ /dev/null
@@ -1,11 +0,0 @@
-# Config file for running tests in Kokoro
-
-# Location of the build script in repository
-build_file: "protobuf/kokoro/linux/ruby24/build.sh"
-timeout_mins: 120
-
-action {
- define_artifacts {
- regex: "**/sponge_log.xml"
- }
-}
diff --git a/kokoro/linux/ruby24/presubmit.cfg b/kokoro/linux/ruby24/presubmit.cfg
deleted file mode 100644
index a1ccfc0..0000000
--- a/kokoro/linux/ruby24/presubmit.cfg
+++ /dev/null
@@ -1,11 +0,0 @@
-# Config file for running tests in Kokoro
-
-# Location of the build script in repository
-build_file: "protobuf/kokoro/linux/ruby24/build.sh"
-timeout_mins: 120
-
-action {
- define_artifacts {
- regex: "**/sponge_log.xml"
- }
-}
diff --git a/kokoro/macos/ruby23/build.sh b/kokoro/macos/ruby23/build.sh
deleted file mode 100755
index 5a29a99..0000000
--- a/kokoro/macos/ruby23/build.sh
+++ /dev/null
@@ -1,12 +0,0 @@
-#!/bin/bash
-#
-# Build file to set up and run tests
-
-# Change to repo root
-cd $(dirname $0)/../../..
-
-# Prepare worker environment to run tests
-KOKORO_INSTALL_RVM=yes
-source kokoro/macos/prepare_build_macos_rc
-
-./tests.sh ruby23
diff --git a/kokoro/macos/ruby23/continuous.cfg b/kokoro/macos/ruby23/continuous.cfg
deleted file mode 100644
index c9b1f61..0000000
--- a/kokoro/macos/ruby23/continuous.cfg
+++ /dev/null
@@ -1,5 +0,0 @@
-# Config file for running tests in Kokoro
-
-# Location of the build script in repository
-build_file: "protobuf/kokoro/macos/ruby23/build.sh"
-timeout_mins: 1440
diff --git a/kokoro/macos/ruby23/presubmit.cfg b/kokoro/macos/ruby23/presubmit.cfg
deleted file mode 100644
index c9b1f61..0000000
--- a/kokoro/macos/ruby23/presubmit.cfg
+++ /dev/null
@@ -1,5 +0,0 @@
-# Config file for running tests in Kokoro
-
-# Location of the build script in repository
-build_file: "protobuf/kokoro/macos/ruby23/build.sh"
-timeout_mins: 1440
diff --git a/kokoro/macos/ruby24/build.sh b/kokoro/macos/ruby24/build.sh
deleted file mode 100755
index 10ac85f..0000000
--- a/kokoro/macos/ruby24/build.sh
+++ /dev/null
@@ -1,12 +0,0 @@
-#!/bin/bash
-#
-# Build file to set up and run tests
-
-# Change to repo root
-cd $(dirname $0)/../../..
-
-# Prepare worker environment to run tests
-KOKORO_INSTALL_RVM=yes
-source kokoro/macos/prepare_build_macos_rc
-
-./tests.sh ruby24
diff --git a/kokoro/macos/ruby24/continuous.cfg b/kokoro/macos/ruby24/continuous.cfg
deleted file mode 100644
index fada028..0000000
--- a/kokoro/macos/ruby24/continuous.cfg
+++ /dev/null
@@ -1,5 +0,0 @@
-# Config file for running tests in Kokoro
-
-# Location of the build script in repository
-build_file: "protobuf/kokoro/macos/ruby24/build.sh"
-timeout_mins: 1440
diff --git a/kokoro/macos/ruby24/presubmit.cfg b/kokoro/macos/ruby24/presubmit.cfg
deleted file mode 100644
index fada028..0000000
--- a/kokoro/macos/ruby24/presubmit.cfg
+++ /dev/null
@@ -1,5 +0,0 @@
-# Config file for running tests in Kokoro
-
-# Location of the build script in repository
-build_file: "protobuf/kokoro/macos/ruby24/build.sh"
-timeout_mins: 1440
