Upgrade to rust 2018
Upgrade to rust 2018

Signed-off-by: Patrik Stas <6c4238a049060e56eb05ce2cae5c82b437da42b8@absa.co.za>

Artemkaaas/indy-sdk,Artemkaaas/indy-sdk,Artemkaaas/indy-sdk,Artemkaaas/indy-sdk,Artemkaaas/indy-sdk,Artemkaaas/indy-sdk,Artemkaaas/indy-sdk,Artemkaaas/indy-sdk,Artemkaaas/indy-sdk,Artemkaaas/indy-sdk,Artemkaaas/indy-sdk,Artemkaaas/indy-sdk,Artemkaaas/indy-sdk