finish attribute & Entity

src/main/sql/schema-v1.sql

src/test/java/com/ic/er/TestAttribute.java

src/test/java/com/ic/er/TestER.java

src/test/java/com/ic/er/TestEntity.java

src/test/java/com/ic/er/TestRelationship.java

src/test/java/com/ic/er/TestView.java

src/test/java/com/ic/er/mapper/attributeMapperTest.java

src/test/java/com/ic/er/mapper/entityMapperTest.java

src/test/java/com/ic/er/mapper/testGraphInfoMapper.java

src/test/java/com/ic/er/mapper/testRelationMapper.java

src/test/java/com/ic/er/mapper/testViewMapper.java

src/test/java/com/ic/er/testMybatis.java