v0.7.0

improvements

• implemented junit4 org.junit.runner.Runner for running org.quackery.Test #21
• expanded Collection contract with tests for size() and isEmpty()

fixes

• recognized assumption exception when running by junit #20

incompatible changes

• removed integration with junit3 by removing junit(Test) method #21
• renamed
  • QuackeryAssertionException to AssertionException
  • QuackeryAssumptionException to AssumptionException
  • Tester to Contract
  • Quacks to Contracts
• deleted Testers class with trivial contracts