Typeorm breaking changes in 0.3.0+ affecting TypeGraphql examples

**Describe the issue**
Typeorm 0.3.0+ has released with many breaking changes for the Typegraphql examples. Notably, all container-related features in Typeorm have been depecreated affecting how TypeDI is used. Also the way to establish a typeorm connection to a DB with Typeorm.createConnection() has been depecrated in favour of Typeorm.DataSource.

At a first glance, the following examples have been affected:

[typeorm-basic-usage](https://github.com/MichalLytek/type-graphql/tree/master/examples/typeorm-basic-usage)
[typeorm-lazy-relations](https://github.com/MichalLytek/type-graphql/tree/master/examples/typeorm-lazy-relations)

**Are you able to make a PR that fix this?**
Not currently

Start with examples/typeorm-basic-usage and examples/typeorm-lazy-relations; inspect their TypeDI setup and TypeORM connection creation. Update both examples for the TypeORM 0.3.0+ APIs and verify that they continue to work against a database.

Written by the indexing model from the issue text.