message: Use the new poplibs API where non-liearities are explicitly inplace
  Summary: Move to the new non-linearities API
  Test Plan: all existing tests (barring the timeout on image_test)
  Reviewers: jakeh, georgep
diff: @@ -518,7 +518,7 @@ StatusOr<poplar::program::Program> CreateReluOp(CompilerResources& res,
  inputs, GetInplaceOutputTensors(graph, res, seq, inst, tensor_map));
  CHECK_EQ(inputs.size(), 1);
  poplar::Tensor t = inputs[0];
  - popnn::relu(graph, t, seq, GetDebugName(inst));
  + popnn::reluInPlace(graph, t, seq, GetDebugName(inst));
  TF_ASSIGN_OR_RETURN(t, BroadcastTensor(t, output_shape));
  @@ -562,7 +562,7 @@ StatusOr<poplar::program::Program> CreateSigmoidOp(
  CHECK_EQ(inputs.size(), 1);
  poplar::Tensor t = inputs[0];
  - popnn::sigmoid(graph, t, seq, GetDebugName(inst));
  + popnn::sigmoidInPlace(graph, t, seq, GetDebugName(inst));
  TF_ASSIGN_OR_RETURN(t, BroadcastTensor(t, output_shape));
  