re-export actix_rt::main macro

[robjtede]

Re-exports actix_rt::main as actix_web::main (and actix_rt::test as actix_web::test_rt since test is already a module). Also bumps minimum rt version to 1.1.1.

Would like to hear thoughts on this. Seems advantageous to remove the requirement for users to add actix-rt as a direct dependency. The question gets asked reasonably often of why two deps are needed for the hello world example.

[cetra3]

I think that makes sense, but would need to update documentation for it. Is there any reason why actix_rt would be used besides the macro? I don't think I've used it directly in my code.

[robjtede]

Using actix_rt::spawn is probably the second most common case for the crate. Then the test macro (I'm not completely sold on re-exporting it like this, if there are objections speak up 😄). If this idea is accepted would update docs, website and examples.

[codecov-commenter]

Codecov Report

Merging #1559 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #1559   +/-   ##
=======================================
  Coverage   51.03%   51.03%           
=======================================
  Files         129      129           
  Lines       12049    12049           
=======================================
  Hits         6149     6149           
  Misses       5900     5900           

Impacted Files	Coverage Δ
src/lib.rs	68.42% <ø> (ø)

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[therealprof]

Sounds like a good idea to me.

[cetra3]

Approved