Optional tenant id checking based on request route path

[ephrimlawrence]

Fix for #27

This PR adds skipTenantCheck option to TenancyModuleOptions. If skipTenantCheck is true for a request, tenant database connection will be bypassed.

As in the example below, the tenant DB connection will be bypassed for all /birds* routes.

TenancyModule.forRoot({
   tenantIdentifier: 'X-TenantId',
   options: {},
   uri: (tenantId: string) => `mongodb://localhost/tenant-${tenantId}`,
   skipTenantCheck: (req) => req.route.path.match(/^\/birds*/) != null,
})

[ephrimlawrence]

@sandeepsuvit any feedback on this PR? We really need the optional tenancy check feature

[sandeepsuvit]

Hi @ephrimlawrence the reason why i kept it on hold is because of difference of opinions on this implementation. Please refer to the following comment

Also there is another PR pending with similar functionality but using a guard implementation.

Please let me know your viewpoint on these.

[Robokishan]

This is very good feature.! any thing you can do this to merge ?
@sandeepsuvit