Add Postgresql Support

[ariepratama]

Hi,
It will be nice if we can add postgresql support for DBWAL

[PraveenSeluka]

Hi @ariepratama

this is straight forward. Since we use JDBC, we will need to add postgres jars and that will work. I see that you have created a PR, will look into it next week. Thanks for your interest.

[ariepratama]

Hi @PraveenSeluka actually that was my initial assumption, turns out we need to adjust sql queries between postgresql and mysql as you can see in my PR.