Remove pgroll sql subcommand (#515)

The `pgroll sql` subcommand adds a dependency on the `sql2pgroll`
package which requires `cgo` due to the `pg_query_go` dependency.

Remove this subcommand until we're able to cross-compile `pgroll` with
`cgo` enabled as part of the release process.

Author: andrew-farries

cmd/root.go

@@ -79,7 +79,6 @@ func Execute() error {
 	rootCmd.AddCommand(migrateCmd())
 	rootCmd.AddCommand(pullCmd())
 	rootCmd.AddCommand(latestCmd())
-	rootCmd.AddCommand(sqlCmd())
 
 	return rootCmd.Execute()
 }