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

Fixes #702

RELNOTES: Add imports attribute to native Python rules.

--
MOS_MIGRATED_REVID=114314430
diff --git a/examples/py_native/BUILD b/examples/py_native/BUILD
index d6fdfa9..5a82223 100644
--- a/examples/py_native/BUILD
+++ b/examples/py_native/BUILD
@@ -7,7 +7,10 @@
 py_binary(
     name = "bin",
     srcs = ["bin.py"],
-    deps = [":lib"],
+    deps = [
+        ":lib",
+        "//examples/py_native/fibonacci",
+    ],
 )
 
 py_library(
@@ -18,7 +21,10 @@
 py_test(
     name = "test",
     srcs = ["test.py"],
-    deps = [":lib"],
+    deps = [
+        ":lib",
+        "//examples/py_native/fibonacci",
+    ],
 )
 
 py_test(
diff --git a/examples/py_native/bin.py b/examples/py_native/bin.py
index f79379a..7b65627 100644
--- a/examples/py_native/bin.py
+++ b/examples/py_native/bin.py
@@ -1,4 +1,6 @@
 """A tiny example binary for the native Python rules of Bazel."""
 from examples.py_native.lib import GetNumber
+from fib import Fib
 
 print "The number is %d" % GetNumber()
+print "Fib(5) == %d" % Fib(5)
diff --git a/examples/py_native/fibonacci/BUILD b/examples/py_native/fibonacci/BUILD
new file mode 100644
index 0000000..c3ee9b0
--- /dev/null
+++ b/examples/py_native/fibonacci/BUILD
@@ -0,0 +1,6 @@
+py_library(
+    name = "fibonacci",
+    srcs = ["fib.py"],
+    imports = ["."],
+    visibility = ["//examples/py_native:__pkg__"],
+)
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)
diff --git a/examples/py_native/test.py b/examples/py_native/test.py
index 811eee1..f9543aa 100644
--- a/examples/py_native/test.py
+++ b/examples/py_native/test.py
@@ -1,6 +1,8 @@
 """A tiny example binary for the native Python rules of Bazel."""
+
 import unittest
 from examples.py_native.lib import GetNumber
+from fib import Fib
 
 
 class TestGetNumber(unittest.TestCase):
@@ -8,6 +10,8 @@
   def test_ok(self):
     self.assertEquals(GetNumber(), 42)
 
+  def test_fib(self):
+    self.assertEquals(Fib(5), 8)
 
 if __name__ == '__main__':
   unittest.main()