allow the checkIfFileExists method to check if 1 or more files exist
changed checkIfFileExists method to show all none existent files. Also improved indentation
adds an import for os.path.exists. Exists is preffered to isFile as it checks for directories as well.
revert checkIfFileExists to check only for files and not folders.
Merge pull request #9 from mjuaji/issue128

allow the checkIfFileExists method to check if 1 or more files exist