write initial code for SwissDict, add tests

Author: eulerkochy

src/swiss_dict.jl

@@ -42,7 +42,6 @@ function SwissDict{K,V}(ps::Pair...) where {K, V}
     end
     return h
 end
-
 SwissDict() = SwissDict{Any,Any}()
 SwissDict(kv::Tuple{}) = SwissDict()
 copy(d::SwissDict) = SwissDict(d)
@@ -473,4 +472,4 @@ end
     is === nothing && return nothing
     i, s = is
     return (v isa KeySet ? v.dict.keys[i] : v.dict.vals[i], s)
-end
+end

test/test_swiss_dict.jl

@@ -347,4 +347,4 @@ end
     empty!(h)
     @test length(h) == 0
     @test length(h.keys) == length(h.vals) == prev_sz
-end
+end