Update to protobuf 0.6.3

[rockneurotiko]

Protobuf 0.5.3 is really old, I think it's good to at least provide a version with 0.6.3 (and probably with 0.7.1 too).

The main change is that now the family_name (StringValue) and the qualifier (BytesValue) doesn't arrives just with the value, it arrives with the original struct {value: X}

[codecov]

Codecov Report

Merging #21 into master will not change coverage.
The diff coverage is 100%.

@@          Coverage Diff           @@
##           master     #21   +/-   ##
======================================
  Coverage    92.2%   92.2%           
======================================
  Files          20      20           
  Lines         308     308           
======================================
  Hits          284     284           
  Misses         24      24

Impacted Files	Coverage Δ
lib/data/chunk_reader.ex	97.22% <100%> (ø)	⬆️

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