Add imports attribute to Bazel native Python rules to allow adding directories to PYTHONPATH.

Fixes #702

RELNOTES: Add imports attribute to native Python rules.

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MOS_MIGRATED_REVID=114314430
diff --git a/examples/py_native/fibonacci/fib.py b/examples/py_native/fibonacci/fib.py
new file mode 100644
index 0000000..645a937
--- /dev/null
+++ b/examples/py_native/fibonacci/fib.py
@@ -0,0 +1,8 @@
+"""An example binary to test the imports attribute of native Python rules."""
+
+
+def Fib(n):
+  if n == 0 or n == 1:
+    return 1
+  else:
+    return Fib(n-1) + Fib(n-2)