--output_file does not support multiple nodes

[dploeger]

Description of problem

• What did you do?
  • Use the --output-file option for octocatalog-diff while running it against multiple target nodes
• What happened?
  • The output file only contains the last analysed node
• What did you expect to happen?
  • The output file contains the diffs of all analysed nodes
• How can someone reproduce the problem?
  • Run octocatalog-diff with the --output-file option and use multiple nodes (-n node1,node2)

Command used and debugging output

$ octocatalog-diff -f production -t target-branch --display-detail-add -n node1,node2 -o octodiff.output
I, [2022-06-21T10:55:51.744356 #123224]  INFO -- : Catalogs compiled for node1
I, [2022-06-21T10:55:51.793838 #123224]  INFO -- : Catalogs compiled for node2
I, [2022-06-21T10:55:52.171791 #123224]  INFO -- : Diffs computed for node1
I, [2022-06-21T10:55:52.253632 #123224]  INFO -- : Diffs computed for node2
I, [2022-06-21T10:55:52.353417 #123224]  INFO -- : Wrote diff to octodiff.output
I, [2022-06-21T10:55:52.354721 #123224]  INFO -- : Wrote diff to octodiff.output
$ head octodiff.output
diff production/node2 target-branch/node2

Platform and version information

• Your OS: Ubuntu 18.03
• Your Ruby version: ruby 2.5.1p57 (2018-03-29 revision 63029) [x86_64-linux-gnu]
• Your version of Puppet: 6.27.0
• Your version of octocatalog-diff: octocatalog-diff 2.1.0