Feature Request: Handling JS Date variables

First of all, thanks for creating/maintaining this amazing library. I'll cut into my request.

Background

I am using sql.js with typeorm to do integration testing rather than spinning up a mysql service for that.

Issue

I noted that if I use Javascript Date objects in the where conditions, it works in production, but fails in tests, because sql.js doesn't convert the dates similar to how node-mysql driver does that.

Expectation

I would love it if sql.js would convert the dates correctly.
For example, take the following example:

const updatedAt = new Date(/*Some date string goes here*/);

// Assume db is setup correctly as explained in ReadMe
db.run("SELECT * FROM test_table WHERE example_column = ?", [updatedAt]);

Now, this fails because sql.js would call updatedAt.toString(). But AFAIK, in node-mysql they call updatedAt.toISOString() (or some valid date string) internally.

Notes

1. Code works with sql.js when we do updatedAt.toISOString() explicitly
2. The error that's being thrown at the moment is:

QueryFailedError: Wrong API use : tried to bind a value of an unknown type (Fri Jan 11 2019 01:01:01 GMT+1100 (Australian Eastern Daylight Time)).

    at new QueryFailedError (/Users/pubudu/Projects/typeorm-test/src/error/QueryFailedError.ts:9:9)
    at SqljsQueryRunner.<anonymous> (/Users/pubudu/Projects/typeorm-test/src/driver/sqljs/SqljsQueryRunner.ts:79:22)

Start by reproducing the db.run example with a JavaScript Date value and inspect the parameter-binding path that produces the reported unknown-type error. The issue mentions SqljsQueryRunner.ts:79:22 in the stack trace; done means Date parameters are accepted with the expected SQL date representation and the existing binding behavior remains covered by a test.