Return New Directory Path of a Change Command
You are given a string representing a system directory path and a string representing a directory change command as arguments. Return the new directory path after the change command has been "executed."
'../' indicates going up one directory, '../../' would mean to go up two directories etc.
- Must return a string
solve('/home/pictures/hawaii/july', '../../florida/may') > '/home/pictures/florida/may'
solve('/Library/Logs/Microsoft', '../../../var/log') > '/var/log'