ansible-roles/alerta#10 Pin API and web-ui version and no longer use master

defaults/main.yml

+alerta_version_api: 8.1.0
+alerta_version_web_ui: 8.0.1

templates/api/Dockerfile

-FROM alerta/alerta-web
+FROM alerta/alerta-web:{{ alerta_version_api }}
 
 USER root
 COPY ./plugins/*.py /tmp/plugins/

templates/webui/Dockerfile

@@ -3,7 +3,7 @@ FROM node:lts-alpine as build-stage
 
 RUN apk add --no-cache git
 WORKDIR /app
-ADD https://github.com/alerta/alerta-webui/archive/master.tar.gz /tmp/webui.tar.gz
+ADD https://github.com/alerta/alerta-webui/archive/v{{ alerta_version_web_ui }}.tar.gz /tmp/webui.tar.gz
 RUN tar zxvf /tmp/webui.tar.gz -C /app --strip-components=1
 RUN npm install
 COPY .env .