Print awscli logs in mint json format

[nitisht]

This PR updates the awscli tests output as per latest mint log format. Fixes: #113

Here is the current log output:

{
  "name": "awscli",
  "duration": "1088",
  "function": "delete_bucket",
  "status": "PASS"
}
{
  "name": "awscli",
  "duration": "1468",
  "function": "aws --endpoint-url http://127.0.0.1:9000 s3api get-object --bucket awscli-mint-test-bucket-32065 --key datafile-1-MB /tmp/datafile-1-MB",
  "status": "PASS"
}
{
  "name": "awscli",
  "duration": "2583",
  "function": "aws --endpoint-url http://127.0.0.1:9000 s3api list-objects --bucket awscli-mint-test-bucket-27359 --prefix datafile-1-MB",
  "status": "PASS"
}
{
  "name": "awscli",
  "duration": "2236",
  "function": "aws --endpoint-url http://127.0.0.1:9000 s3api create-multipart-upload --bucket awscli-mint-test-bucket-6807 --key awscli-mint-test-bucket-6807-object",
  "status": "PASS"
}
{
  "name": "awscli",
  "duration": "1485",
  "function": "aws --endpoint-url http://127.0.0.1:9000 s3api copy-object --bucket awscli-mint-test-bucket-30165 --key datafile-1-MB-copy --copy-source awscli-mint-test-bucket-30165/datafile-1-MB",
  "status": "PASS"
}
{
  "name": "awscli",
  "duration": "1453",
  "function": "aws --endpoint-url http://127.0.0.1:9000 s3 presign s3://awscli-mint-test-bucket-18511/datafile-1-MB",
  "status": "PASS"
}
{
  "name": "awscli",
  "duration": "2051",
  "function": "aws --endpoint-url http://127.0.0.1:9000 s3 cp /mint/data/datafile-65-MB s3://awscli-mint-test-bucket-26066/datafile-65-MB",
  "status": "PASS"
}
{
  "name": "awscli",
  "duration": "2258",
  "function": "aws --endpoint-url http://127.0.0.1:9000 s3 sync /mint/data s3://awscli-mint-test-bucket-30221/",
  "status": "PASS"
}
{
  "name": "awscli",
  "duration": "2179",
  "function": "aws --endpoint-url http://127.0.0.1:9000 s3api list-objects-v2 --bucket awscli-mint-test-bucket-15618 --prefix datafile-1-MB --max-keys=-1",
  "status": "PASS"
}
{
  "name": "awscli",
  "duration": "4827",
  "function": "aws --endpoint-url http://127.0.0.1:9000 s3api list-objects-v2 --bucket awscli-mint-test-bucket-15618 --prefix datafile-1-MB --max-keys=-1",
  "status": "PASS"
}