we change mymysql to go-sql-driver and use insert unhex()
  for any dangerous data type.

  1. remove Index_Comment in ShowIndex function
  2. remove mysql client deps in Makefile

not fix too many connections yet

  go test ./... -update

  COL.015 text/blob default value only tobe `NULL`;
  COL.012 text/blob `NOT NULL` CONSTRAINT may be danagerous;

  RemoveSQLComment trim space

  1. go version move into Makefile
  2. add golden test for ast
  3. explainAbleSQL use tidb parser also

  multi-line comment will cause line counter error, when
  -report-type=lint

  remove bom before auditing

  -check-config will check
  * YAML format
  * OnlineDSN connection
  * TestDSN connection

  add doc for blacklist config

  1. fix -config arg parse bug
  2. code & comment lint

  #47 pretty print function `format` endless loop
  #37 -report-type not in (markdown, html) will not print score