needed to add import path of cwd

Without this I got this error:

<pre>
shai@comp ~/Projects/tryfer <master> python examples/tracing-client.py
Traceback (most recent call last):
  File "examples/tracing-client.py", line 22, in <module>
    from tryfer.tracers import push_tracer, DebugTracer, EndAnnotationTracer
ImportError: No module named tryfer.tracers
</pre>