mypy 0.570 uses 1-based column numbers
mypy 0.570 uses 1-based column numbers

In order to properly support this, check for mypy's version number
and adjust the column number in the resulting LintMatch object. This is
the only thread-safe way and using PythonLinter's
`context_sensitive_executable_path` will yield us the same exeutable
as was used for the actual lint.

Closes #27
Closes #29

fredcallaway/SublimeLinter-contrib-mypy