Adjust code to pass eslint no-var

[cjbarth]

No description provided.

[codecov]

Codecov Report

Merging #311 (035426f) into master (b425626) will not change coverage.
The diff coverage is 90.29%.

@@           Coverage Diff           @@
##           master     #311   +/-   ##
=======================================
  Coverage   81.04%   81.04%           
=======================================
  Files           7        7           
  Lines         865      865           
=======================================
  Hits          701      701           
  Misses        164      164           

Impacted Files	Coverage Δ
lib/c14n-canonicalization.js	67.96% <81.48%> (ø)
lib/signed-xml.js	81.27% <90.15%> (ø)
lib/exclusive-canonicalization.js	86.76% <92.30%> (ø)
lib/enveloped-signature.js	95.45% <100.00%> (ø)
lib/file-key-info.js	100.00% <100.00%> (ø)
lib/utils.js	96.66% <100.00%> (ø)

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