Update build to get latest snapshots

[planetf1]

Currently the postgres connector is using the 2.6-SNAPSHOT version of egeria from the odpi artifactory repository. These snapshots are built automatically when merges hit master. (the egeria docker image, which we would use in integration testing is built from the same github action)

By default maven will only refresh any snapshots it's using when either a) 24 hours has passed [configurable] b) the -U option is provided to maven. For gradle we need to follow the recommendations at https://discuss.gradle.org/t/how-to-get-gradle-to-download-newer-snapshots-to-gradle-cache-when-using-an-ivy-repository/7344 ie

configurations.all {
    // check for updates every build
    resolutionStrategy.cacheChangingModulesFor 0, 'seconds'
}
  dependencies {
    compile group: "group", name: "projectA", version: "1.1-SNAPSHOT", changing: true
}

This suggests key is adding 'changing:true' to any dependencies we need to be absolutely up to date for the most recent build.

This is relevant where we have changes in base egeria and immediately want to rebuild the connector and pick up those changes. This affects not only an automated build, but also a developers environment

Opening for consideration

[planetf1]

Update The postgres connector is referring to the jfrog repository in build.gradle. this is no longer being updated, so should be removed. all versions (snapshot or not) should be obtained from maven central

@wbittles Also I notice the build is referring to 2.5-SNAPSHOT. This needs updating to either 2.8-SNAPSHOT or 2.7 (ie release) depending on how stable you reckon the base is. I'd go with the release if possible

[planetf1]

Note that dependabot is now active and is recommending updates. @wbittles You could merge these (or update manually and they will auto close) - probably appropriate now , or decide it's more appropriate to stick with 2.8-SNAPSHOT.