Update mongo-driver package to 1.5.1

[sravankasu]

Hi,

I'm trying to install go-swagger which has a dependency on go-openapi/loads. Looks like there is an indirect dependency on the xdg/stringprep package which is causing go get github.com/go-swagger/go-swagger/cmd/swagger to fail

#11 139.6 go get: github.com/go-swagger/go-swagger@v0.26.1 requires
#11 139.6       github.com/go-openapi/loads@v0.20.1 requires
#11 139.6       go.mongodb.org/mongo-driver@v1.4.5 requires
#11 139.6       github.com/xdg/stringprep@v0.0.0-20180714160509-73f8eece6fdc: invalid version: unknown revision 73f8eece6fdc

The mongo-driver package was recently updated to fix this issue: mongodb/mongo-go-driver#624

Please update the mongo-driver package to 1.5.1

[sravankasu]

Looks like the fix was backported to the mongo-go-driver package.