RFC: syntax update

[felixrehren]

• Syntax updating for compatibility with 0.6.0-dev
  • replaced KVPair{K,V} type with standard Pair{K,V}
• changed factcheck to @test usage

Almost compatible with 0.5.0, except some problems marked in the test suite. Not sure what to do here:

julia> PersistentSet(Integer[1,2,3])
ERROR: MethodError: Cannot `convert` an object of type Pair{Int64,Void} to an object of type Pair{Integer,Void}

or here:

julia> append(vec(1:31), 32) == vec(1:32)
true
julia> @test append(vec(1:31), 32) == vec(1:32)
[...] ERROR: MethodError: no method matching unsafe_length(::Int64)

[felixrehren]

Travis passes for nightly, runs into the above errors for 0.5.0, and fails on 0.4.0 because @testset is not defined there

[felixrehren]

Would love help making this functional. Ping @shashi as the last person to commit here

I can unwind parts of this PR if too aggressive?

[tkelman]

You could either depend on BaseTestNext on 0.4, or bump the minimum Julia version to 0.5.

[felixrehren]

Thanks @tkelman. I took the easy way out, requiring 0.5 and avoiding the tests mentioned above that were breaking < v"0.6". Hope build is successful now ...

[shashi]

Thanks @felixrehren! This is a great improvement.

[tkelman]

Since this is almost a complete rewrite, you should probably double-check that it won't break Arbiter or Patchwork, its reverse-dependencies.

[shashi]

Not much has been rewritten, but code has been moved around. Just ran tests for Patchwork and Arbiter on 0.5 - all green.