Release v0.3.1

This release brings improvements and bug fixes.

• Improvements
  • More robust _add_coin.py
  • 10 additional cryptocoin definitions
  • New exchange added: coins-e
  • Exchanges updates with list of supported coins
  • Updated Litecoin tx fee to reflect new Litecoin release
• Bug fixes
  • Handling case where redeem can't be done due to unknown exchange rate