New upstream version 3.13.1

.github/CONTRIBUTING.md

.github/ISSUE_TEMPLATE.md

.github/ISSUE_TEMPLATE/bug_report.md

.github/ISSUE_TEMPLATE/feature_request.md

.github/ISSUE_TEMPLATE/question.md

CHANGELOG.md

README.md

benchmarks/README.md

benchmarks/pom.xml

...ks/src/main/java/okhttp3/benchmarks/ApacheHttpClient.java

benchmarks/src/main/java/okhttp3/benchmarks/Benchmark.java

...rks/src/main/java/okhttp3/benchmarks/NettyHttpClient.java

benchmarks/src/main/java/okhttp3/benchmarks/OkHttp.java

benchmarks/src/main/java/okhttp3/benchmarks/OkHttpAsync.java

...marks/src/main/java/okhttp3/benchmarks/UrlConnection.java

bom/pom.xml

mockwebserver/pom.xml

...rc/main/java/okhttp3/internal/duplex/MwsDuplexAccess.java

...ver/src/main/java/okhttp3/mockwebserver/MockResponse.java

...er/src/main/java/okhttp3/mockwebserver/MockWebServer.java