I am seeing the same thing when incrementing our Confluence app to use newer Confluence versions and datasets. Reproduced with Confluence 6.13.4 and 6.14.2:
[INFO] Starting confluence...
[INFO] Configured Artifact: com.atlassian.confluence.plugins:confluence-plugin-test-resources:6.14.2:zip
Downloading: https://maven.atlassian.com/repository/public/com/atlassian/confluence/plugins/confluence-plugin-test-resources/6.14.2/confluence-plugin-test-resources-6.14.2.zip
Apr 17, 2019 2:37:06 PM org.apache.maven.wagon.providers.http.httpclient.impl.execchain.RetryExec execute
INFO: I/O exception (java.net.SocketException) caught when processing request: Connection reset
This is in an environment where everything used to work.
Edit: Figured out that if you update to the latest SDK then everything works fine. But also keep an eye out for: Getting error on `atlas-run` which hit me.