Database & Testing update

### In this PR are some structural changes to tests:
 - No database URLs or credentials are stored in the project (source code, config or otherwise)
 - All Database info & creds are retrieved via `CrsProperties`
 - All tests which interact with the database extend `AbstractTestWithDatabaseConnectivity`
 - `AbstractTestWithDatabaseConnectivity` does a refresh of the target database before each test run

### Necessary changes:
 - Add properties which contain DB URL, user & password to filesystem properties file (usually found at /apps/apps-config/conf-registration-api-properties.xml).  See below for example.

### Possible gotchas:
 - Do not EVER put production creds as the unittest properties like this, as a test run could wipe out the production database.  There is no reason to do so.  Production creds should reside only in the application properties.  Actually you could try, but I'll likely make it that the prod DB would ignore connections things other than app servers.

Example properties:
```xml
    <!-- unittest database server connection info -->
    <entry key="unittestDatabaseUrl">jdbc:postgresql://localhost/eventhub_unittest</entry>
    <entry key="unittestDatabaseUsername">[username]</entry>
    <entry key="unittestDatabasePassword">[password]</entry>
```
Yes, produciton and stage will be defined correctly by the chef deployment recipes, but that has nothing to do with the unittest database.  The unittest database is separate and should be handled separately.

Think about it this way.  If the unittest database credentials were configured using the same properties as the normal database credentials, consider this scenario:

Locally I configure my environment to run against the stage database for testing, (or more extreme, against production for data verification).  I finish my work, commit my changes and as a last step run the unittest suite from my CLI.  If the database properties are still pointed at stage or production, I've now wiped out the entire database.