chore(project): 添加项目配置文件和忽略规则

- 添加 Babel 配置文件支持 ES6+ 语法转换
- 添加 ESLint 忽略规则和配置文件
- 添加 Git 忽略规则文件
- 添加 Travis CI 配置文件
- 添加 1.4.2 版本变更日志文件
- 添加 Helm 图表辅助模板文件
- 添加 Helm 忽略规则文件

script/client/at/db/oracle.sql

@@ -0,0 +1,19 @@
+-- for AT mode you must to init this sql for you business database. the seata server not need it.
+CREATE TABLE undo_log
+(
+    id            NUMBER(19)    NOT NULL,
+    branch_id     NUMBER(19)    NOT NULL,
+    xid           VARCHAR2(128) NOT NULL,
+    context       VARCHAR2(128) NOT NULL,
+    rollback_info BLOB          NOT NULL,
+    log_status    NUMBER(10)    NOT NULL,
+    log_created   TIMESTAMP(0)  NOT NULL,
+    log_modified  TIMESTAMP(0)  NOT NULL,
+    PRIMARY KEY (id),
+    CONSTRAINT ux_undo_log UNIQUE (xid, branch_id)
+);
+
+COMMENT ON TABLE undo_log IS 'AT transaction mode undo table';
+
+-- Generate ID using sequence and trigger
+CREATE SEQUENCE UNDO_LOG_SEQ START WITH 1 INCREMENT BY 1;