comments in file break SQHExecute file on current buffer

Given this file

-- A small set of manual tests to run.

-- Run :SQHExecute over this line without a visual selection. It should run the correct query
SELECT * FROM symfony.gig LIMIT 5;

-- Run :SQHExecute over this but with a visual selection. It should run the correct query
-- (badly formatted on purpose)
SELECT
*
FROM
symfony.gig WHERE
YEAR(date) > 2017;

-- Run the following commands
-- SQHExecute! SELECT * FROM symfony.gig
-- SQHShowDatabases

-- Run this entire file with
-- SQHExecuteFile

-- Run it as an argument with
-- :SQHExecuteFile /home/joe/.config/nvim/plugged/SQHell.vim/test/manual_tests/tests.sql

It won't run because the first few lines are comments. What we need to do is pass it through a function that strips out MySQL comments.

Steps to take

Create a function in autoload/mysql.vim called mysql#stripComments(content)
:g/^--/d to remove all the comments starting with --
Throw some contents of files at it in a test

joereynolds / SQHell.vim

comments in file break SQHExecute file on current buffer #38

Steps to take