Add driver dialect for Snowflake

[hundredwatt]

*gosnowflake.SnowflakeDriver is compatible with the postgres dialect

This PR adds:

"*gosnowflake.SnowflakeDriver": &postgres, 

to driverDialect, which required reformatting the map literal and made the diff messy 😄

[codecov]

Codecov Report

Merging #14 into master will decrease coverage by 2.22%.
The diff coverage is 0.00%.

@@            Coverage Diff             @@
##           master      #14      +/-   ##
==========================================
- Coverage   86.84%   84.61%   -2.23%     
==========================================
  Files           2        2              
  Lines          76       78       +2     
==========================================
  Hits           66       66              
- Misses          6        8       +2     
  Partials        4        4              

Impacted Files	Coverage Δ
dialect.go	90.90% <0.00%> (-9.10%)	⬇️

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[jimsmart]

Thanks for your pull request, appreciated.

I've just added support for the Snowflake driver, as described in your initial commit, in v0.0.5.

The main issue with supporting Snowflake is that we have no way to easily test it, being a commercial service with no open/free offering (beyond a free trial) — this makes it somewhat difficult to test locally or to set up in a CI environment.

Due to this, I see no value in adding non-running tests for Snowflake to the codebase, currently.

According to their docs identifier escaping in Snowflake is performed using double quotes, which is the same as Postgres — so I have not included the changes from your later commit providing unescaped identifiers for Snowflake.

HTH

[jimsmart]

I've filed an issue to track this lack of testing.