Added Dependency Injection Groups and Set support.

[alexruperez]

What is the purpose of this pull request?

[x] New feature.
[x] Documentation update.

What changes did you make?

• Dependency Injection Groups.
• Set support.

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This change is 

[codeclimate]

Code Climate has analyzed commit 1ded4b1 and detected 0 issues on this pull request.

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[codecov]

Codecov Report

Merging #21 (1ded4b1) into master (f8e37f4) will increase coverage by 0.21%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master      #21      +/-   ##
==========================================
+ Coverage   93.77%   93.99%   +0.21%     
==========================================
  Files          19       19              
  Lines        1045     1082      +37     
==========================================
+ Hits          980     1017      +37     
  Misses         65       65              

Impacted Files	Coverage Δ
Sources/Inject/Inject.swift	97.16% <100.00%> (+0.50%)	⬆️
Sources/Inject/InjectStorage.swift	100.00% <100.00%> (ø)
Sources/Storage/DelegatedStorage.swift	95.65% <100.00%> (+0.06%)	⬆️
Sources/UserDefault/UserDefaultsStorage.swift	100.00% <100.00%> (ø)
Tests/SecurePropertyStorageTests/InjectTests.swift	98.73% <100.00%> (+0.14%)	⬆️
.../SecurePropertyStorageTests/UserDefaultTests.swift	90.25% <100.00%> (+0.41%)	⬆️

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