fix: 7.0/cli/Dockerfile to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-DEBIAN9-CURL-466505
- https://snyk.io/vuln/SNYK-DEBIAN9-CURL-466508
- https://snyk.io/vuln/SNYK-DEBIAN9-FILE-473950
- https://snyk.io/vuln/SNYK-DEBIAN9-LIBXML2-429367
- https://snyk.io/vuln/SNYK-DEBIAN9-OPENSSL-2426305

7.0/cli/Dockerfile

@@ -1,4 +1,4 @@
-FROM php:7.0-cli
+FROM php:7.3-cli
 MAINTAINER louisbl <louisbl@beltramo.me>
 
 RUN apt-get update && apt-get install -y \