Add timeout/max-retries to LFTP test connection

[nicolemah99]

This PR:

• Adds max_connection_retries to config.yml to set the number of connection attempts to a meter
  • If not set it defaults to 1
  • max_retries in lftp works with reconnect_interval_base to set the time (sec) in between retries
  • reconnect_interval_base is currently set to 5 in test_meter_connection.sh
• data_pipeline.sh checks to make sure max_connection_retries is between (1-10) (I chose 10 as a max can be changed)