Rename non-technical occurrences of FBSnapshotTestCase to iOSSnapshotTestCase
Rename non-technical occurrences of FBSnapshotTestCase to iOSSnapshotTestCase

See #https://github.com/uber/ios-snapshot-test-case/issues/2
peacemoon/ios-snapshot-test-case,material-foundation/ios-snapshot-test-case,peacemoon/ios-snapshot-test-case,material-foundation/ios-snapshot-test-case,material-foundation/ios-snapshot-test-case,peacemoon/ios-snapshot-test-case,material-foundation/ios-snapshot-test-case