Update redox_syscall requirement from 0.2 to 0.3

[dependabot[bot]]

Updates the requirements on redox_syscall to permit the latest version.

Dependabot will resolve any conflicts with this PR as long as you don't alter it yourself. You can also trigger a rebase manually by commenting @dependabot rebase.

---

Dependabot commands and options

You can trigger Dependabot actions by commenting on this PR:

• @dependabot rebase will rebase this PR
• @dependabot recreate will recreate this PR, overwriting any edits that have been made to it
• @dependabot merge will merge this PR after your CI passes on it
• @dependabot squash and merge will squash and merge this PR after your CI passes on it
• @dependabot cancel merge will cancel a previously requested merge and block automerging
• @dependabot reopen will reopen this PR if it is closed
• @dependabot close will close this PR and stop Dependabot recreating it. You can achieve the same result by closing it manually
• @dependabot ignore this major version will close this PR and stop Dependabot creating any more for this major version (unless you reopen the PR or upgrade to it yourself)
• @dependabot ignore this minor version will close this PR and stop Dependabot creating any more for this minor version (unless you reopen the PR or upgrade to it yourself)
• @dependabot ignore this dependency will close this PR and stop Dependabot creating any more for this dependency (unless you reopen the PR or upgrade to it yourself)

[codecov-commenter]

Codecov Report

Merging #36 (a30523b) into master (748fee5) will increase coverage by 1.02%. The diff coverage is n/a.

@@            Coverage Diff             @@
##           master      #36      +/-   ##
==========================================
+ Coverage   80.95%   81.98%   +1.02%     
==========================================
  Files          11       11              
  Lines        2694     2670      -24     
==========================================
+ Hits         2181     2189       +8     
+ Misses        513      481      -32     

Impacted Files	Coverage Δ
src/archive.rs	71.07% <0.00%> (-6.58%)	:arrow_down:
src/error.rs	35.71% <0.00%> (-4.29%)	:arrow_down:
src/entry.rs	57.85% <0.00%> (-0.09%)	:arrow_down:
tests/all.rs	99.57% <0.00%> (+<0.01%)	:arrow_up:
src/header.rs	71.45% <0.00%> (+6.74%)	:arrow_up:

Help us with your feedback. Take ten seconds to tell us how you rate us.