For foreign key migrations instead of integer() use unsignedInteger() type or integer()->unsigned(), otherwise you may get SQL errors.
Schema::create('employees', function (Blueprint $table) {
$table->unsignedInteger('company_id');
$table->foreign('company_id')->references('id')->on('companies');
// ...
});
You can also use unsignedBigInteger() if that other column is bigInteger() type.
Schema::create('employees', function (Blueprint $table) {
$table->unsignedBigInteger('company_id');
});