Remove Unicode characters from README.md

Unfortunately for dear ole' Ionut, Berkshelf cannot handle
uploading cookbooks with files that contain Unicode characters.
When uploading, you get the following error:

Change-Id: Id3341e1e24cf7ca468cc94cabf8920f96689e08c
STDERR: ERROR: Encoding::InvalidByteSequenceError: "\xC8" on US-ASCII