Library close transaction

[maranqz]

pgx closes transaction on error.
Then the lib returns missing error of "commit unexpectedly resulted in rollback".

[hound672]

I checked this behavior in #76
If I return trm.ErrSkip in transaction section transaction will be commited.
Is this correct?

[maranqz]

ErrSkip doesn't connect with ErrTxCommitRollback.
ErrSkip allows to commit on an application error not a database.

I think, I can close this issue, because the pgx docs said: PostgreSQL accepts COMMIT on aborted transactions, but px is treated as ROLLBACK.

The libs cannot fix this behavior.