Improve cram test output messages

As suggested by @huddlej in PR #902
Tests originally implemented by @corneliusroemer

Author: jameshadfield

tests/functional/export_v2.t

@@ -110,26 +110,31 @@ This should fail with a helpful error message.
   ERROR: None of the possible id columns (('strain', 'name')) were found in the metadata's columns ('invalid_id', 'div', 'mutation_length')
   [1]
 
-# export_v2/location_node-data2.json was produced by a mismatched version
-# Running without --skip-validation should result in an error
-# Message printed: "Validation of auspice_config3.json failed."
+Node-data JSONs produced from a different major version of augur
+are not allowed.
   $ ${AUGUR} export v2 \
   >   --tree export_v2/tree.nwk \
   >   --node-data export_v2/div_node-data.json export_v2/location_node-data2.json \
   >   --auspice-config export_v2/auspice_config3.json \
-  >   --output "$TMP/dataset4.json" &>/dev/null
+  >   --output "$TMP/dataset4.json"
+  ERROR: Augur version incompatibility detected: the JSON export_v2/location_node-data2.json was generated by \{'program': 'augur', 'version': '13.1.2'\}, which is incompatible with the current augur version \([.0-9]+\). We suggest you rerun the pipeline using the current version of augur. (re)
   [2]
 
-# Skipping validation gives us the same results as `location_node-data.json`
+
+Skipping validation allows mismatched augur versions to be used without error.
+(Note the stderr/stdout output is detailed here, including 2 empty lines)
   $ ${AUGUR} export v2 \
   >   --tree export_v2/tree.nwk \
   >   --node-data export_v2/div_node-data.json export_v2/location_node-data2.json \
   >   --auspice-config export_v2/auspice_config2.json \
   >   --output "$TMP/dataset5.json" \
-  >   --skip-validation &>/dev/null
-
+  >   --skip-validation
+  WARNING: You didn't provide information on who is maintaining this analysis.
+  
+  
+Check the output from the above command against its expected contents
   $ python3 "$TESTDIR/../../scripts/diff_jsons.py"  export_v2/dataset2.json "$TMP/dataset5.json" \
   >   --exclude-paths "root['meta']['updated']"
   {}
 
-  $ popd > /dev/null
+  $ popd > /dev/null