fix: 7.1/cli/Dockerfile to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-DEBIAN10-CURL-466510
- https://snyk.io/vuln/SNYK-DEBIAN10-DPKG-2847944
- https://snyk.io/vuln/SNYK-DEBIAN10-OPENSSL-1569403
- https://snyk.io/vuln/SNYK-DEBIAN10-OPENSSL-2807585
- https://snyk.io/vuln/SNYK-DEBIAN10-OPENSSL-2933515

7.1/cli/Dockerfile

@@ -1,4 +1,4 @@
-FROM php:7.1-cli
+FROM php:7.3-cli
 MAINTAINER louisbl <louisbl@beltramo.me>
 
 RUN apt-get update && apt-get install -y \