Add to documentation how to change PostgreSQL version using Gradle

[mfvanek]

Hi there,
could you please add some tips to readme file about using this project with Gradle.

The main issue is how to change PostgreSQL version.
There are several ways to do it depending on used Gradle version.

For Gradle 4.6+ you have to activate feature IMPROVED_POM_SUPPORT in settings.gradle file.
enableFeaturePreview('IMPROVED_POM_SUPPORT')
And then add the following rows to your build.gradle file

testImplementation 'io.zonky.test.postgres:embedded-postgres-binaries-bom:11.7.0'
testImplementation 'io.zonky.test:embedded-postgres:1.2.6'

For Gradle 5+ activation of the additional feature is no longer required. You can use 'enforcedPlatform':

testImplementation 'io.zonky.test:embedded-postgres:1.2.6'
testImplementation enforcedPlatform('io.zonky.test.postgres:embedded-postgres-binaries-bom:11.7.0')

I think it would be very helpful for developers.

[tomix26]

Hi, you're right, I'll update the readme. Thanks.