Handle failures from `@test_logs`

[jakobjpeters]

Related to #130.

RROR: MethodError: no method matching to_xml(::Test.LogTestFailure)
The function `to_xml` exists, but no method is defined for this combination of argument types.


Closest candidates are:
  to_xml(::Test.Pass)
   @ TestReports ~/.julia/packages/TestReports/yVV91/src/to_xml.jl:225
  to_xml(::Test.Fail)
   @ TestReports ~/.julia/packages/TestReports/yVV91/src/to_xml.jl:236
  to_xml(::Test.Broken)
   @ TestReports ~/.julia/packages/TestReports/yVV91/src/to_xml.jl:242
  ...

Stacktrace:
  [1] to_xml(v::TestReports.ReportingResult{Test.LogTestFailure})
    @ TestReports ~/.julia/packages/TestReports/yVV91/src/to_xml.jl:254
  [2] (::TestReports.var"#to_xml##0#to_xml##1"{ReportingTestSet})(result::TestReports.ReportingResult{Test.LogTestFailure})
    @ TestReports ~/.julia/packages/TestReports/yVV91/src/to_xml.jl:195
  [3] iterate
    @ ./generator.jl:48 [inlined]
  [4] collect_to!(dest::Vector{EzXML.Node}, itr::Base.Generator{Vector{Test.Result}, TestReports.var"#to_xml##0#to_xml##1"{ReportingTestSet}}, offs::Int64, st::Int64)
    @ Base ./array.jl:848
  [5] collect_to_with_first!(dest::Vector{EzXML.Node}, v1::EzXML.Node, itr::Base.Generator{Vector{Test.Result}, TestReports.var"#to_xml##0#to_xml##1"{ReportingTestSet}}, st::Int64)
    @ Base ./array.jl:826
  [6] _collect(c::Vector{Test.Result}, itr::Base.Generator{Vector{Test.Result}, TestReports.var"#to_xml##0#to_xml##1"{ReportingTestSet}}, ::Base.EltypeUnknown, isz::Base.HasShape{1})
    @ Base ./array.jl:820
  [7] collect_similar(cont::Vector{Test.Result}, itr::Base.Generator{Vector{Test.Result}, TestReports.var"#to_xml##0#to_xml##1"{ReportingTestSet}})
    @ Base ./array.jl:732
  [8] map(f::Function, A::Vector{Test.Result})
    @ Base ./abstractarray.jl:3372
  [9] to_xml(ts::ReportingTestSet)
    @ TestReports ~/.julia/packages/TestReports/yVV91/src/to_xml.jl:194
 [10] (::TestReports.var"#report##0#report##1")(result::ReportingTestSet)
    @ TestReports ~/.julia/packages/TestReports/yVV91/src/to_xml.jl:146
 [11] iterate
    @ ./generator.jl:48 [inlined]
 [12] collect_to!(dest::Vector{EzXML.Node}, itr::Base.Generator{Vector{Test.AbstractTestSet}, TestReports.var"#report##0#report##1"}, offs::Int64, st::Int64)
    @ Base ./array.jl:848
 [13] collect_to_with_first!
    @ ./array.jl:826 [inlined]
 [14] _collect(c::Vector{Test.AbstractTestSet}, itr::Base.Generator{Vector{Test.AbstractTestSet}, TestReports.var"#report##0#report##1"}, ::Base.EltypeUnknown, isz::Base.HasShape{1})
    @ Base ./array.jl:820
 [15] collect_similar
    @ ./array.jl:732 [inlined]
 [16] map
    @ ./abstractarray.jl:3372 [inlined]
 [17] report(testsets::Vector{Test.AbstractTestSet})
    @ TestReports ~/.julia/packages/TestReports/yVV91/src/to_xml.jl:145
 [18] (::var"#2#3")(io::IOStream)
    @ Main ./none:20
 [19] open(::var"#2#3", ::String, ::Vararg{String}; kwargs::@Kwargs{})
    @ Base ./io.jl:410
 [20] open(::Function, ::String, ::String)
    @ Base ./io.jl:407
 [21] top-level scope
    @ none:19
 [22] eval(m::Module, e::Any)
    @ Core ./boot.jl:489
 [23] exec_options(opts::Base.JLOptions)
    @ Base ./client.jl:283
 [24] _start()
    @ Base ./client.jl:550
ERROR: LoadError: TestReports failed to generate the report.
See error log above.

[oxinabox]

The code for it is here
So it should just be a matter of adding a overload