Fix path to bunbled OAuthSimple
Fix path to bunbled OAuthSimple

Signed-off-by: Tom Castleman <df60106d6df4df7346d371018d28d1d13ede4f12@b3-it.com>

elliotchance/xero-api,tkrish/XeroOAuth-PHP,slightlydiff/yii2-xero,XeroAPI/XeroOAuth-PHP,whytewaters/XeroOAuth-PHP