Update to go-bt 0.0.4

[galt-tr]

0.0.3 was getting checksum mismatches from github so went ahead and upgraded.

[codecov]

Codecov Report

Merging #9 (96d99cf) into master (24d444d) will not change coverage.
The diff coverage is 0.00%.

@@           Coverage Diff           @@
##           master       #9   +/-   ##
=======================================
  Coverage   88.02%   88.02%           
=======================================
  Files           9        9           
  Lines         359      359           
=======================================
  Hits          316      316           
  Misses         22       22           
  Partials       21       21           

Impacted Files	Coverage Δ
transaction.go	92.30% <0.00%> (ø)

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