fixed - security scheme mapping

ref #148

issue resource expansion.

• issue's resource expansion. (ref #145 )

setter for issue security level

• setter for issue security(#143 )

get/delete comment

• added get/delete comment method.(#141)

add version create method.

• add version create(#138 )
• update doc for api token(#135 )
• cookie login support

priority field maybe empty.

previous commit was not merge into master.

see #137.

Priority field may be empty.

see #137

Do not set default version field

see #132 #131

fix Call to a member function isEmpty() on null

see #130

fixed Empty assignee is included request data.

see #126