build: use specific version of alpine

Author: gsdevme

Dockerfile

@@ -1,4 +1,4 @@
-FROM alpine:3
+FROM alpine:3.15
 
 ENV SLACK_SIGNING_SECRET=""
 ENV PORT=8080
@@ -7,4 +7,4 @@ ENV SSH_KNOWN_HOSTS="/etc/ssh/ssh_known_hosts"
 RUN apk add --no-cache openssh-client && ssh-keyscan -H github.com >> /etc/ssh/ssh_known_hosts
 
 ENTRYPOINT ["/gitops-commit"]
-COPY gitops-commit /
+COPY gitops-commit /