Update README for 2.0 development

[codecov[bot]]

Codecov Report

Merging #152 into master will decrease coverage by 0.01%. The diff coverage is n/a.

@@            Coverage Diff             @@
##           master     #152      +/-   ##
==========================================
- Coverage   99.24%   99.22%   -0.02%     
==========================================
  Files          19       19              
  Lines        2122     2069      -53     
==========================================
- Hits         2106     2053      -53     
  Misses         16       16

Impacted Files	Coverage Δ
lib/google/gax/grpc.rb	93.75% <0%> (-0.37%)	:arrow_down:
lib/google/gax/settings.rb	99.01% <0%> (-0.07%)	:arrow_down:
spec/google/gax/bundling_spec.rb	99.69% <0%> (-0.02%)	:arrow_down:
lib/google/gax/bundling.rb	99.37% <0%> (-0.01%)	:arrow_down:
lib/google/gax/operation.rb	100% <0%> (ø)	:arrow_up:
spec/google/gax/util_spec.rb	100% <0%> (ø)	:arrow_up:
spec/google/gax/error_spec.rb	100% <0%> (ø)	:arrow_up:
lib/google/gax/errors.rb	100% <0%> (ø)	:arrow_up:
spec/google/gax/settings_spec.rb	100% <0%> (ø)	:arrow_up:
spec/google/gax/grpc_spec.rb	100% <0%> (ø)	:arrow_up:
... and 1 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more Δ = absolute <relative> (impact), ø = not affected, ? = missing data Powered by Codecov. Last update 962214d...295d74f. Read the comment docs.

[codecov[bot]]

Codecov Report

Merging #152 into master will not change coverage. The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #152   +/-   ##
=======================================
  Coverage   99.24%   99.24%           
=======================================
  Files          19       19           
  Lines        2122     2122           
=======================================
  Hits         2106     2106           
  Misses         16       16

---

Continue to review full report at Codecov.

Legend - Click here to learn more Δ = absolute <relative> (impact), ø = not affected, ? = missing data Powered by Codecov. Last update 962214d...295d74f. Read the comment docs.