Facets filtering

Add facets filtering support

Add init by app key for ViSearch client

Merge pull request #7 from thehung111/master

DR-1342 Add ViSearch client init by app key

Update user agent to visearch

Merge pull request #5 from thehung111/master

update user agent to visearch

version 1.0.1 release

user agent for tracking

version 1.0 release

Merge pull request #1 from thehung111/master

MOBILE-70 Swift SDK client first release