Add support for Postgis to JDBC driver

[kiview]

This is an alternative implementation of #708, relying completely on the existing PostgreSQLContainer class.

[wimdeblauwe]

typo os -> of

[wimdeblauwe]

Look ok for me, except for the typo remark I made on the PostgisContainerProvider.java file

[kiview]

Cool, so this would work for your use case?

@rnorth WDYT, does it provide value to the project?
As mentioned in the other PR, for normal instantiation, it's fine to use PostgreSQLContainer with constructor argument.

[wimdeblauwe]

My use case is an integration test with Spring Boot. For this, I specify:

spring.datasource.url=jdbc:tc:postgis:10://localhost/mydb

in application-integration-test.properties with @ActiveProfiles("integration-test"). If that URL will trigger testcontainers to start the proper postgis image, then it should work.

[kiview]

Yes, it will exactly support those kind of use cases.
I'll wait for feedback from @rnorth and then we can merge, thanks for your input and contributions @wimdeblauwe 🙂

[rnorth]

Released for preview in 1.9.0-rc2, to be published on Bintray.