Add tests

[avinassh]

I have added a few tests, this will also make sure that changes made in PR #23 work nicely.

• I have kept the tests in /tests as we need to import the driver. Keeping them inside the package doesn't work due to cyclic imports
• Added tests mostly for the ws package since http APIs don't support transactions or prepared statements
• The test Test_TimeStamp doesn't pass yet, I think this library doesn't handle timestamp fields

Running Tests

To run tests, set env variable pointing to the libsql database and then run make test

$ export LIBSQL_TEST_DB_URL=wss://della-avinassh.turso.io?jwt=eyJ...sCg
$ go test -v -count=1 ./...

CI/CD

Adding to Github workflow is easy. You need to add the LIBSQL_TEST_DB_URL as repository secret first, then tests can run automatically on PR

I have added the workflow file in my repo and have setup automated tests - https://github.com/avinassh/libsql-client-go/pull/1

If this is okay, then I can add the workflow file to this PR

[haaawk]

Thanks @avinassh I left few comments but looks great otherwise.

[haaawk]

Timestamps are not supported yet. We need support from Turso to implement it. It's on its way.

[haaawk]

Thanks @avinassh