Add imports to address compiler warning messages

Added these imports:
import scala.language.postfixOps
import scala.language.implicitConversions
import scala.language.existentials
Added imports to prevent compiler warnings

Added these imports:
import scala.language.postfixOps
import scala.language.implicitConversions
import scala.language.existentials
Merge pull request #294 from carl297r/master

Added imports to reduce compiler warnings