Some diacritics e.g., É not rendering in HTML properly

[fuhrmanator]

My BibTeX file has

@TechReport{SoumareFuhrman2011,
  author      = {Soumar{\'{e}}, Hadamon and Fuhrman, Christopher P.},
  title       = {Framework for assessing understandability impact of design patterns},
  institution = {{{\'{E}}}cole de technologie sup{\'{e}}rieure},
  year        = {2011},
  number      = {ETS-RT-2011-001},
  date        = {2011},
  location    = {Montr{\'{e}}al, Canada},
  owner       = {Cris},
  pages       = {38},
  timestamp   = {2014.02.08},
  url         = {http://espace2.etsmtl.ca/3766/},
}

The lowercase é is fine, but the uppercase​ É renders as 'E.

The braces are generated by Jabref when I apply a utf8-to-latex filtering script, so I'm pretty sure it's correct. There's another similar but simpler case with

  author       = {Champagne, Roger and Fuhrman, Christopher and Lefebvre, {\'E}ric},

Have a look at http://bl.ocks.org/fuhrmanator/raw/7fc2424e983433aad69c5b69f8ff988a/

[fuhrmanator]

Actually, I see it's an Έ (greek capital epsilon). I did a PR #12 that fixes the bug.