bump Erlang to 21.3.8.1

Bump OTP 21.3 version used in test and in the resulting image to
21.3.8.1. Add travis tests for OTP 22.0.

.gitlab-ci.yml

@@ -22,7 +22,11 @@ before_script:
 
 build:otp-21:
   <<: *build_otp
-  image: erlang:21.3.3-alpine
+  image: erlang:21.3.8.1-alpine
+
+build:otp-22:
+  <<: *build_otp
+  image: erlang:22.0-alpine
 
 .check:otp: &check_otp
   stage: test
@@ -38,13 +42,20 @@ build:otp-21:
 
 check:otp-21:
   <<: *check_otp
-  image: erlang:21.3.3-alpine
+  image: erlang:21.3.8.1-alpine
   dependencies:
     - build:otp-21
 
+check:otp-22:
+  <<: *check_otp
+  image: erlang:22.0-alpine
+  dependencies:
+    - build:otp-22
+
 docker:
   image: docker:git
   stage: container
+  dependencies: []
   services:
     - docker:dind
   script:

.travis.yml

@@ -8,7 +8,8 @@ language: erlang
 otp_release:
  - 21.1.4
  - 21.2.7
- - 21.3.3
+ - 21.3.8.1
+ - 22.0
 
 install: "true"
 
@@ -42,7 +43,7 @@ script:
 jobs:
   include:
     - stage: docker
-      otp_release: 21.3.3
+      otp_release: 21.3.8.1
       script:
         - docker build -t $BUILD_IMAGE -f docker/Dockerfile .
       after_success:

docker/Dockerfile

@@ -1,7 +1,7 @@
 # -- build-environment --
 # see https://docs.docker.com/engine/userguide/eng-image/multistage-build/
 
-FROM erlang:21.3.3-alpine AS build-env
+FROM erlang:21.3.8.1-alpine AS build-env
 
 WORKDIR /build
 RUN     apk update && apk --no-cache upgrade && \

rebar.config

@@ -19,7 +19,7 @@
 	{ergw_aaa, {git, "git://github.com/travelping/ergw_aaa", {ref, "21457c7"}}}
 ]}.
 
-{minimum_otp_vsn, "21.0"}.
+{minimum_otp_vsn, "21.1"}.
 
 {profiles, [
 	    {test, [