+pro create akka-http-parent project as an anchor to run aggregate tasks on
=htc #16488 add missing assertions in tests

 - replaced pure `===` by `shouldEqual`
 - fixed the backport of spray/spray#927 in ae8c47acc170907ee9c8dfbcb946b400035f6877
 - fixed HttpHeaderParserSpec
+doc apply new docs design to akka-docs-dev
Merge pull request #16457 from spray/w/introduce-http-aggregate-project

+pro create akka-http-parent project as an anchor to run aggregate tasks on
Merge pull request #16551 from ktoso/docs-dev-styling

+doc apply new docs design to akka-docs-dev
Merge pull request #16489 from spray/w/16488-fix-http-tests

=htc #16488 add missing assertions in tests
+doc quickstart docs for akka streams, initial version