Switch to JDK 13 for releasing and CI build.

[anuraaga]

Also adds JRE exact version to paths so version can be updated without manually clearing CI cache

I found that JDK12 has this bug when generating javadoc

https://bugs.openjdk.java.net/browse/JDK-8222091

I sort of wonder how we've been releasing so far (do we release on Windows?), but I guess it's a good time to switch to JDK13 for release.

[codecov]

Codecov Report

Merging #2424 into master will decrease coverage by 0.02%.
The diff coverage is n/a.

@@             Coverage Diff              @@
##             master    #2424      +/-   ##
============================================
- Coverage     72.99%   72.96%   -0.03%     
+ Complexity    10753    10749       -4     
============================================
  Files           946      946              
  Lines         41804    41804              
  Branches       5206     5206              
============================================
- Hits          30515    30503      -12     
- Misses         8627     8639      +12     
  Partials       2662     2662

Impacted Files	Coverage Δ	Complexity Δ
.../linecorp/armeria/internal/Http2GoAwayHandler.java	57.5% <0%> (-2.5%)	14% <0%> (-1%)
...a/com/linecorp/armeria/client/HttpChannelPool.java	76.22% <0%> (-2.46%)	57% <0%> (-2%)
...om/linecorp/armeria/client/HttpSessionHandler.java	59.84% <0%> (-2.37%)	28% <0%> (-2%)
...rp/armeria/common/stream/DefaultStreamMessage.java	90.71% <0%> (-1.43%)	54% <0%> (-1%)
.../main/java/com/linecorp/armeria/server/Server.java	81% <0%> (-1.17%)	28% <0%> (ø)
...inecorp/armeria/server/HttpResponseSubscriber.java	85.53% <0%> (+1.27%)	72% <0%> (+3%)	⬆️

---

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[trustin]

Thanks, @anuraaga

[minwoox]

👍

[ikhoon]

Thanks! @anuraaga

[trustin]

I sort of wonder how we've been releasing so far (do we release on Windows?)

I've been releasing on Linux. No idea it worked so far. 🙈