message: Removes tanh option from yogi optimizers.
diff: @@ -202,18 +202,9 @@ message OnlineYogiParameters {
  // \beta_2 from Algorithm 2 in the paper.
  float beta2 = 3;
  - // x -> copysign(1, x) (i.e., return 1 for an input of +0 rather than 0).
  - message SignActivation {}
  -
  - // x -> tanh(x * 10)
  - message TanhActivation {}
  -
  - // Activation to use to replace sign function in v_t update in Algorithm 2 of
  - // paper.
  - oneof activation {
  - SignActivation sign = 6;
  - TanhActivation tanh = 7;
  - }
  + // Reserved ids corresponding to removed tanh activation.
  + reserved 6; // sign
  + reserved 7; // tanh
  }
  // The online Yogi optimizer does not implement hyper-parameter update; use the
  @@ -241,18 +232,9 @@ message ProximalYogiParameters {
  // A constant trading off adaptivity and noise.
  float epsilon = 5;
  - // x -> copysign(1, x) (i.e., return 1 for an input of +0 rather than 0).
  - message SignActivation {}
  -
  - // x -> tanh(x * 10)
  - message TanhActivation {}
  -
  - // Activation to use to replace sign function in v_t update in Algorithm 2 of
  - // paper.
  - oneof activation {
  - SignActivation sign = 8;
  - TanhActivation tanh = 9;
  - }
  + // Reserved ids corresponding to removed tanh activation.
  + reserved 8; // sign
  + reserved 9; // tanh
  }
  // Status of using gradient accumulation (doing two passes over the input
  