Fix issue #4 leetcode#ResetProblem unknown function

Author: ianding1

plugin/leetcode.vim

@@ -19,7 +19,7 @@ if !exists('g:leetcode_debug')
 endif
 
 command! -nargs=0 LeetCodeList call leetcode#ListProblems()
-command! -nargs=0 LeetCodeReset call leetcode#ResetProblem(0)
+command! -nargs=0 LeetCodeReset call leetcode#ResetSolution(0)
 command! -nargs=0 LeetCodeTest call leetcode#TestSolution()
 command! -nargs=0 LeetCodeSubmit call leetcode#SubmitSolution()
 command! -nargs=0 LeetCodeSignIn call leetcode#SignIn(1)