added missing line breaks

when expectations are not satisfied, the error message is hard to read as it contains indentation without corresponding line breaks:

    GroupExpectation: not satisfied, unordered, Interval: 1
      GroupExpectation: not satisfied, unordered, Interval: 1
        Expectation: satisfied, Method: Bar.doSomeCalculations (ubyte[] []) @system ExpectedCalls: 1    Expectation: not satisfied, Method: Bar.doSomeCalculations (ubyte[] []) @system ExpectedCalls: 1
        Calls: 0    Expectation: not satisfied, Method: Bar.doSomeCalculations (ubyte[] []) @system ExpectedCalls: 1
        Calls: 0