COL.014 support NVARCHAR
  COL.013 support zero time

- Fix RuleImplicitConversion(ARG.003) with INT and DECIMAL
- Fix RuleImplicitConversion duplicate suggest when use IN () operator

  fix #213 CLA.001 NO WHERE CONDITION
  fix PRIMARY key append to multi column index

  1. update change log
  2. fix ERR parse bug

  go test -update ./...

  https://github.com/XiaoMi/soar/issues/98

  col = 1 OR col IS NULL
  col1 = 1 OR col2 = 1

  sleep(), benchmark(), get_lock, release_lock() are
  dangerous function may not be used in online.

  WHERE col = col = '' and col1 = 'xx'

* import bats for cli test

  https://github.com/sstephenson/bats

* add simple test case for cli use bats

* format main.bats add env

* replace main_test.sh with main.bats

  make explain suggestion sorted
  make index suggestion sorted

* add test database world_x

* update bats golden result

* make docker add 180s timeout

  1. add timeout for docker start
  2. add not explain able sql test case into explain_test.go

* explain info Using index VS Using index condition

  remove nonappearence key from explain extra info

* add timeout for test

* fix #178  JSON datatype only support utf8mb4 now

* splitstatement support optimizer hint

  https://dev.mysql.com/doc/refman/8.0/en/optimizer-hints.html
  https://dev.mysql.com/doc/refman/8.0/en/comments.html

* vendor daily update

* format explain suggestion content

not fix too many connections yet

  RES.009 not consider about "and", "or"... Operator in
  BinaryOperationExpr

  RuleTimePrecision
  MySQL 5.6.4+ New time data type, support time precision to microsecond

  column.Tp may be nil when checking

a new config arg 'min-cardinality' for index column selection

  bit type not config as int, when two columns compare will
  give ARG.003 suggestion.

  fix #154, #157 by the way

  不建议使用连续判断
  SELECT * FROM tbl WHERE col = col = 'abc'