align: trim down print statements for insertions

[joverlee521]

Context

I noticed that augur align prints insertions to stdout, which can potentially lead to workflow logs being flooded with long insertion sequences as noted in nextstrain/hmpv#8. I think we can trim down these print statements since the same insertions are output to a file. It's not entirely clear to me from reading #449 why insertions need to be print to stdout in addition to the output CSV file.

Possible solution

1. Remove the print statements entirely
2. Only print to stdout for debugging i.e. when the command is run with the --debug flag
3. Keep the print statements because of (?) and always redirect stdout from augur align to a log file in workflows.

[jameshadfield]

That was a long time ago! No reason for them to go to stdout as far as I can see. Option 1.