Release of v0.1.0-rc1

New Feature

• Support MySQL protocol，arana can be used as a MySQL proxy.
• Support as a MySQL proxy for single Database and sharding Database.
• Support MySQL read write split according to weight config.
• Support insert, update, delete, show etc SQL statement.
• Support simple query SQL statement, for limit x,y, simple order by & group by, aggregate function.
• Support etcd as dynamic configuration center.
• Support snowflake as distributed primary key.
• Support single Database transaction.
• Support MySQL SQL parsing and generate abstract syntax tree.
• Support multiple sharding algorithms, such as mod, hashMd5, hashCrc32, hashBKDR.
• Support JavaScript expression and function expression for sharding algorithms.