Context should be WeakReference to make it avaiable for Garbage Collector and not lead to MemoryLeak

[MahmoudMabrok]

https://github.com/zasadnyy/z-validations/blob/9cc6d5c8d0689205959c96bd0b12e1e4f0cf5301/z-validations/z-validations-library/src/main/java/ua/org/zasadnyy/zvalidations/Form.java#L40