Allow sqlanalyser to be set in `makemigrations --lint`

[iamstej]

The ability to provide the SQL Analyser to use when running the migration linter has been implemented for the lintmigrations flow; this allows for usage of the library when using unknown database vendors e.g. postgis.

Would it be possible to introduce this into the makemigrations flow too? Either via a command argument or to take into consideration the options set in the django settings file.

It currently runs through the get_sql_analyser_class_from_db_vendor function which checks for postgre.

[David-Wobrock]

Hi @iamstej

Thanks for submitting the issue!
See that should fix this issue and add this feature #214 :)