diff --git a/CI/.drone.yml b/CI/.drone.yml
deleted file mode 100644
index 4066ded433..0000000000
--- a/CI/.drone.yml
+++ /dev/null
@@ -1,98 +0,0 @@
-kind: pipeline
-type: docker
-name: java11-test
-steps:
-# test Java 11 HTTP client
-- name: java11-test
-  image: openjdk:11.0
-  commands:
-  - ./mvnw --quiet clean install -Dorg.slf4j.simpleLogger.defaultLogLevel=error
-  - ./mvnw --quiet verify -Psamples.droneio -Dorg.slf4j.simpleLogger.defaultLogLevel=error
-  # test java native client
-  - ./mvnw clean test -f samples/client/petstore/java/native/pom.xml
-  - ./mvnw clean test -f samples/client/petstore/java/native-async/pom.xml
-  - ./mvnw clean test -f samples/openapi3/client/petstore/java/native/pom.xml
-  # test all generators with fake petstore spec (2.0, 3.0)
-  - /bin/bash bin/utils/test-fake-petstore-for-all.sh
-  # generate test scripts
-  - /bin/bash bin/tests/run-all-test
-
----
-kind: pipeline
-type: docker
-name: nim-client-test
-steps:
-# test nim client
-- name: nim-client-test
-  image: nimlang/nim
-  commands:
-  - (cd samples/client/petstore/nim/ && nim c sample_client.nim)
-
----
-kind: pipeline
-type: docker
-name: protobuf-schema-test
-steps:
-# test protobuf schema generator
-- name: protobuf-schema-test
-  image: nanoservice/protobuf-go
-  commands:
-  - protoc --version
-  - mkdir /var/tmp/go/
-  - cd samples/config/petstore/protobuf-schema
-  - protoc --go_out=/var/tmp/go/ services/*
-  - protoc --go_out=/var/tmp/go/ models/*
-
----
-kind: pipeline
-type: docker
-name: aspnetcore-test
-steps:
-# test aspnetcore 3.x
-- name: aspnetcore-test
-  image: mcr.microsoft.com/dotnet/core/sdk:3.1
-  commands:
-  - (cd samples/server/petstore/aspnetcore-3.1/ && /bin/sh build.sh)
-  - (cd samples/server/petstore/aspnetcore-3.0/ && /bin/sh build.sh)
-
----
-kind: pipeline
-type: docker
-name: ocaml-test
-steps:
-# test ocaml petstore client
-- name: ocaml-test
-  image: ocaml/opam2:4.07
-  commands:
-  - sudo apt-get -y install m4
-  - cd samples/client/petstore/ocaml
-  - opam install ppx_deriving_yojson cohttp ppx_deriving cohttp-lwt-unix 
-  - opam pin add ocaml-migrate-parsetree 1.3.1
-  - eval $(opam env)
-  - sudo chmod -R 777 .
-  - dune build --build-dir=./_build
-
----
-kind: pipeline
-type: docker
-name: haskell-client-test
-steps:
-# test haskell client
-- name: haskell-client-test
-  image: haskell:8.10.4
-  commands:
-  - (cd samples/client/petstore/haskell-http-client/ && stack --allow-different-user --install-ghc --no-haddock-deps haddock --fast && stack --allow-different-user test --fast)
-
----
-kind: pipeline
-type: docker
-name: erlang
-steps:
-# test erlang client and server
-- name: erlang
-  image: erlang:alpine
-  commands:
-  - (cd samples/client/petstore/erlang-client && rebar3 compile)
-  - (cd samples/client/petstore/erlang-proper && rebar3 compile)
-  # comment out as the tests pass locally but not in the CI
-  #- (cd samples/server/petstore/erlang-server && rebar3 compile)
diff --git a/CI/.travis.yml.ios b/CI/.travis.yml.ios
deleted file mode 100644
index 31e0df6392..0000000000
--- a/CI/.travis.yml.ios
+++ /dev/null
@@ -1,37 +0,0 @@
-sudo: required
-language: objective-c
-osx_image: xcode10.3
-before_install:
-  - export SW=`pwd`
-  - rvm list
-  #- rvm use 2.3.3
-  - gem environment
-  - gem install bundler -N 
-  - gem install cocoapods -v 1.2.1 -N 
-  - gem install xcpretty -N 
-  - pod --version
-  # comment out below to avoid errors
-  #- pod repo update
-  #- pod setup --silent > /dev/null
-  #- mkdir -p ~/.local/bin
-  #- export PATH=$HOME/.local/bin:$PATH
-  ## start local petstore server
-  #- git clone -b docker --single-branch https://github.com/wing328/swagger-samples
-  #- cd swagger-samples/java/java-jersey-jaxrs
-  #- sudo mvn jetty:run &
-  #- cd $SW
-
-  # show host table to confirm petstore.swagger.io is mapped to localhost
-  - cat /etc/hosts
-  # show java version
-  - java -version
-  # show brew version
-  - brew --version
-  # show xcpretty version
-  - xcpretty -v
-  # show go version
-  - go version
-
-script:
-  # run integration tests defined in maven pom.xml
-  - mvn --no-snapshot-updates -q --batch-mode verify -Psamples.ios -Dmaven.javadoc.skip=true
diff --git a/CI/.travis.yml.jdk6 b/CI/.travis.yml.jdk6
deleted file mode 100644
index ced240e446..0000000000
--- a/CI/.travis.yml.jdk6
+++ /dev/null
@@ -1,29 +0,0 @@
-dist: trusty
-sudo: required
-language: java
-addons:
-  apt:
-    packages:
-      - openjdk-6-jdk
-jdk: openjdk6
-
-cache:
-  directories:
-  - $HOME/.m2
-  - $HOME/.ivy2
-  - $HOME/.gradle/caches/
-  - $HOME/.gradle/wrapper/
-
-install:
-   - jdk_switcher use openjdk6 
-   - java -version
-   - curl -s "https://get.sdkman.io" | bash
-   - source "$HOME/.sdkman/bin/sdkman-init.sh"
-   - sdk version
-   - sdk install gradle 2.9
-   - sdk list gradle
-   - sdk version
-   - gradle --version
-
-script:
-  - cd samples/client/petstore/java/jersey2-java6 && gradle test