Pin Centos image

jklukas · jklukas · commit 2e62aac3c7f6 · 2020-06-22T12:53:32.000-04:00
We're seeing all test runs currently fail (see [example failure](https://app.circleci.com/pipelines/github/mozilla-services/mozilla-pipeline-schemas/1666/workflows/2af886d5-3764-4da0-9d51-bab9ff994611/jobs/3706/steps). This looks to be due to "diff" not being available in the centos8 image published last week.
diff --git a/Dockerfile b/Dockerfile
@@ -1,4 +1,4 @@
-FROM centos:centos8
+FROM centos:centos8.1.1911
 LABEL maintainer="Firefox Data Platform"
 
 # Install the appropriate software

Original file line number	Diff line number	Diff line change
`@@ -1,4 +1,4 @@`
`1`		`-FROM centos:centos8`
	`1`	`+FROM centos:centos8.1.1911`
`2`	`2`	`LABEL maintainer="Firefox Data Platform"`
`3`	`3`
`4`	`4`	`# Install the appropriate software`