Fixed clippy warning and updated DecodeError

[VictorKoenders]

• Fixed the clippy Eq warning.
• Added DecodeError::Io (We were dropping the IO error before)
• Removed PartialEq on DecodeError

[codecov]

Codecov Report

Merging #574 (dd770c5) into trunk (3a4f299) will increase coverage by 1.38%.
The diff coverage is 66.66%.

@@            Coverage Diff             @@
##            trunk     #574      +/-   ##
==========================================
+ Coverage   54.58%   55.97%   +1.38%     
==========================================
  Files          50       50              
  Lines        4437     4279     -158     
==========================================
- Hits         2422     2395      -27     
+ Misses       2015     1884     -131     

Impacted Files	Coverage Δ
compatibility/src/membership.rs	100.00% <ø> (ø)
compatibility/src/rand.rs	100.00% <ø> (ø)
compatibility/src/sway.rs	100.00% <ø> (ø)
src/error.rs	0.00% <ø> (ø)
src/features/serde/mod.rs	47.82% <ø> (ø)
tests/issues/issue_474.rs	96.42% <ø> (ø)
tests/issues/issue_500.rs	100.00% <ø> (ø)
tests/serde.rs	98.07% <ø> (ø)
src/features/impl_std.rs	66.34% <28.57%> (ø)
tests/basic_types.rs	98.00% <33.33%> (-1.34%)	⬇️
... and 6 more

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.