*several* typos in README.md

[tobiKaboom]

line 14: currently says "OPeNDAP require...", but OPeNDAP is the subject and third person, thus requires a final s. correct sentence: "OPeNDAP requires..."
line 182: currently says "Coverage reports are being generate...", but this is incorrect. the correct sentence is: "Coverage reports are being generated..."

then we have a bunch of phrases which could be better, but aren't really errors.
line 183: currently says "artefacts". artefact is british english, artifact is american english, you guys are american, thus you should correct it to "artifacts" and make the british mad.
line 79: same thing, "utilises" should become "utilizes".

that's it. bai