aws-scala-tools v0.21.0

• #61: Updated AWS Java SDK from 1.11.218 to 1.11.269:
  • Added new regions aliases: Ningxia and Paris
  • Added new instance types: m5, c5, x1e, h1, p3
  • Updated AMIs to 2017.09.1
• #62: Fixed generateTemporaryLink expiration date (now + time offset)