Removed Makefile as Go1 makes this unnecessary.

Makefile

@@ -1,11 +0,0 @@
-include $(GOROOT)/src/Make.inc
-
-TARG=github.com/tealeg/xslx
-GOFILES=\
-	doc.go\
-	lib.go\
-	sharedstrings.go\
-	workbook.go\
-	worksheet.go\
-
-include $(GOROOT)/src/Make.pkg