Run `GC.start` after importing batch of records in `Index#import` to prevent memory leaks on large datasets
Run `GC.start` after importing batch of records in `Index#import` to prevent memory leaks on large datasets

GC.start after consecutive batch imports causes a memory leak.
While importing 6 million records, the stack grew from 200mb to ~5GB.
This fixes that issue.

Closes #658

Telmate/tire,HenleyChiu/tire,doximity/tire,elbuo8/retire,tklee/tire_shiphawk,iamrahulroy/retire,mavenlink/retire,brijeshgpt7/retire,rubydubee/retire,zaharpecherin/retire,fabn/retire,karmi/retire,dbose/retire,1776/tire,ChapterMedia/tire