add addAttachFileTest
use copy to move file
Merge branch 'story_7111' of https://github.com/ezScrum/ezScrum into story_7111

Conflicts:
	java/ntut/csie/ezScrum/issue/sql/service/internal/MantisAttachFileService.java
	test/ntut/csie/ezScrum/issue/sql/service/internal/MantisAttachFileServiceTest.java
	test/ntut/csie/ezScrum/issue/sql/service/internal/MantisServiceTest.java