Add GUID and UUID as common initialisms.

Fixes #55.

Signed-off-by: David Symonds <dsymonds@golang.org>
diff --git a/lint.go b/lint.go
index b8cb605..d6e72a2 100644
--- a/lint.go
+++ b/lint.go
@@ -486,6 +486,7 @@
 	"CSS":   true,
 	"DNS":   true,
 	"EOF":   true,
+	"GUID":  true,
 	"HTML":  true,
 	"HTTP":  true,
 	"HTTPS": true,
@@ -504,6 +505,7 @@
 	"TTL":   true,
 	"UI":    true,
 	"UID":   true,
+	"UUID":  true,
 	"URI":   true,
 	"URL":   true,
 	"UTF8":  true,