ValueError `repo.branches.get('branch_no_exist/')` trailing slashes in branch names

if i have a repo and call

>> 'branch_no_exist' in repo.branches
False

as expected, but

>> 'branch_no_exist/' in repo.branches
Traceback (most recent call last):

  pygit2/repository.py", line 1156, in get
    return self[key]
 pygit2/repository.py", line 1144, in __getitem__
    branch = self._repository.lookup_branch(name, GIT_BRANCH_LOCAL)
ValueError: cannot locate local branch 'branch_no_exist/'

Given branch names Shouldn't end in a slash, but the error is not complaining about this.

should repository.lookup_branch be returning None in this case?

从 pygit2/repository.py 中 get 方法以及 traceback 所示的 getitem 路径开始，然后分别复现对不存在分支的查找，测试带和不带尾部斜杠的情况。检查现有的分支查找测试，并将完成标准定义为一致处理带尾部斜杠的情况，同时通过回归测试覆盖该情况。