[ymeng] Encapsulate flat object list
[ymeng] Try to use data manupulation strategy to save/update/remove object
[ymeng] Switch 'assertThat' to 'org.junit' version to fix issue: 'java.lang.NoSuchMethodError: org.hamcrest.Matcher.describeMismatch(Ljava/lang/Object;Lorg/hamcrest/Description;)V'
[ymeng] Describe expected item in matchers
[ymeng] join collection items to string
[ymeng] Use insert-strategy to insert new data
[ymeng] Rename class
[ymeng] Return a copy of fields in flat-object