Display real error when analyze fails

[pbrudnick]

Bug Description

We need a clear and consistent error message when hank fails since parallelization added in #80

To Reproduce

When some rule analyze function fails.

Expected Behavior

Show the real error maybe catching it before.

rebar3 Logs

===> exit analyzing files: badrpc
Stack: [{rpc,check,2,[{file,"rpc.erl"},{line,703}]},
        {hank,analyze,4,
              [{file,"/Users/pablo/dev/SemanticSugar/boodah/_build/default/plugins/rebar3_hank/src/hank.erl"},
               {line,24}]},
        {rebar3_hank_prv,do,1,
                         [{file,"/Users/pablo/dev/SemanticSugar/boodah/_build/default/plugins/rebar3_hank/src/rebar3_hank_prv.erl"},
                          {line,52}]},
        {rebar_core,do,2,
                    [{file,"/private/var/folders/9q/v8hcq64x27ngs4j59hfqtj_h0000gn/T/rebar3-3.14.2/src/rebar_core.erl"},
                     {line,155}]},
        {rebar3,run_aux,2,
                [{file,"/private/var/folders/9q/v8hcq64x27ngs4j59hfqtj_h0000gn/T/rebar3-3.14.2/src/rebar3.erl"},
                 {line,181}]},
        {rebar3,main,1,
                [{file,"/private/var/folders/9q/v8hcq64x27ngs4j59hfqtj_h0000gn/T/rebar3-3.14.2/src/rebar3.erl"},
                 {line,66}]},
        {escript,run,2,[{file,"escript.erl"},{line,758}]},
        {escript,start,1,[{file,"escript.erl"},{line,277}]}]
===> Uncaught error in rebar_core. Run with DIAGNOSTIC=1 to see stacktrace or consult rebar3.crashdump
===> Uncaught error: {error,<<"badrpc">>}