Updates Simperium Pod
Merge remote-tracking branch 'origin/release/4.2' into issues/1966-sppersistentmutabledictionary-crash

Conflicts:
	Pods/Pods.xcodeproj/project.pbxproj
Merge pull request #1968 from wordpress-mobile/issues/1966-sppersistentmutabledictionary-crash

Fixes Crash in SPPersistentMutableDictionary