Refactor ApiCall

[blowmage]

This PR does the following:

• Simplifies ApiCall
  • Remove params_extractor and exception_transformer.
  • Rename ApiCall::Options (was CallOptions).
  • Renames Options#apply_defaults
• Renames RetryPolicy#apply_defaults
  • Make this be more consistent with Options#apply_defaults.
• Adds the following procs to ApiCall#call:
  • format_response to format response objects.
  • Will be used to format longrunning and paged response objects.
  • operation_callback to yield operation objects
  • Useful for accessing trailing metadata.
  • stream_callback to yield every streamed response object.
• Update Operations
  • Add ApiCall::Options argument to RPC to methods.
  • Add Operation RetryPolicy and update wait_for_done? to use it.
• Update OperationsClient
• Remove BackoffSettings.
• Remove MILLIS_PER_SECOND.

[closes #151, closes #165, closes #173]

[codecov[bot]]

Codecov Report

Merging #178 into master will decrease coverage by 0.69%. The diff coverage is 97.05%.

@@            Coverage Diff            @@
##           master     #178     +/-   ##
=========================================
- Coverage   98.52%   97.83%   -0.7%     
=========================================
  Files          27       28      +1     
  Lines        1496     1522     +26     
=========================================
+ Hits         1474     1489     +15     
- Misses         22       33     +11

Impacted Files	Coverage Δ
lib/google/gax.rb	100% <ø> (ø)	:arrow_up:
lib/google/gax/operation.rb	100% <100%> (ø)	:arrow_up:
.../google/gax/api_call/retry_policy/settings_test.rb	100% <100%> (ø)	:arrow_up:
test/google/gax/api_call/retry/raise_test.rb	100% <100%> (ø)	:arrow_up:
...oogle/gax/paged_enumerable/invalid_request_test.rb	100% <100%> (ø)	:arrow_up:
lib/google/gax/api_call.rb	100% <100%> (+2.27%)	:arrow_up:
test/google/gax/api_call/options_test.rb	100% <100%> (ø)
test/google/gax/api_call/retry/retry_test.rb	98.36% <100%> (ø)	:arrow_up:
...ax/paged_enumerable/valid_request_response_test.rb	100% <100%> (ø)	:arrow_up:
lib/google/gax/api_call/retry_policy.rb	100% <100%> (ø)	:arrow_up:
... and 7 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 91b9d4b...b17e119. Read the comment docs.

[codecov-io]

Codecov Report

Merging #178 into master will decrease coverage by 0.69%. The diff coverage is 97.05%.

@@            Coverage Diff            @@
##           master     #178     +/-   ##
=========================================
- Coverage   98.52%   97.83%   -0.7%     
=========================================
  Files          27       28      +1     
  Lines        1496     1522     +26     
=========================================
+ Hits         1474     1489     +15     
- Misses         22       33     +11

Impacted Files	Coverage Δ
lib/google/gax.rb	100% <ø> (ø)	:arrow_up:
lib/google/gax/operation.rb	100% <100%> (ø)	:arrow_up:
.../google/gax/api_call/retry_policy/settings_test.rb	100% <100%> (ø)	:arrow_up:
test/google/gax/api_call/retry/raise_test.rb	100% <100%> (ø)	:arrow_up:
...oogle/gax/paged_enumerable/invalid_request_test.rb	100% <100%> (ø)	:arrow_up:
lib/google/gax/api_call.rb	100% <100%> (+2.27%)	:arrow_up:
test/google/gax/api_call/options_test.rb	100% <100%> (ø)
test/google/gax/api_call/retry/retry_test.rb	98.36% <100%> (ø)	:arrow_up:
...ax/paged_enumerable/valid_request_response_test.rb	100% <100%> (ø)	:arrow_up:
lib/google/gax/api_call/retry_policy.rb	100% <100%> (ø)	:arrow_up:
... and 7 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 91b9d4b...e72336f. Read the comment docs.

[codecov-io]

Codecov Report

Merging #178 into master will increase coverage by 0.1%. The diff coverage is 99.54%.

@@            Coverage Diff            @@
##           master     #178     +/-   ##
=========================================
+ Coverage   98.52%   98.63%   +0.1%     
=========================================
  Files          27       27             
  Lines        1496     1538     +42     
=========================================
+ Hits         1474     1517     +43     
+ Misses         22       21      -1

Impacted Files	Coverage Δ
lib/google/gax/operation.rb	100% <100%> (ø)	:arrow_up:
.../google/gax/api_call/retry_policy/settings_test.rb	100% <100%> (ø)	:arrow_up:
test/google/gax/operation_test.rb	100% <100%> (ø)	:arrow_up:
test/google/gax/api_call/retry/raise_test.rb	100% <100%> (ø)	:arrow_up:
...oogle/gax/paged_enumerable/invalid_request_test.rb	100% <100%> (ø)	:arrow_up:
lib/google/gax/api_call.rb	100% <100%> (+2.27%)	:arrow_up:
test/google/gax/api_call/options_test.rb	100% <100%> (ø)
test/google/gax/api_call/retry/retry_test.rb	98.36% <100%> (ø)	:arrow_up:
lib/google/gax/operation/retry_policy.rb	100% <100%> (ø)
...ax/paged_enumerable/valid_request_response_test.rb	100% <100%> (ø)	:arrow_up:
... and 9 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 91b9d4b...ca84b4f. Read the comment docs.

[blowmage]

this kind of simplification is long overdue!

There is much more coming...

[blowmage]

The GAPIC side of this change can be found in googleapis/gapic-generator-ruby#108.