Alternate RetryConfigBuilder to group relevant configs together for easier use

[raghavan20]

• AlternateRetryConfigBuilder is the alternate implementation
• Usage is described using AlternateRetryConfigBuilder
• Contains few config groups
• Many subclasses are designed mutable for use like Builders
• Many subclasses could be extracted to become parent level classes in their own files
• Some classes do use defaults

Please suggest improvements / feel free to change code

[coveralls]

Pull Request Test Coverage Report for Build 333

• 57 of 70 (81.43%) changed or added relevant lines in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage decreased (-2.09%) to 94.778%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
src/main/java/com/evanlennick/retry4j/config/AlternateRetryConfigBuilder.java	57	70	81.43%
<!--	Total:	57	70

Totals
Change from base Build 331:	-2.09%
Covered Lines:	490
Relevant Lines:	517

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💛 - Coveralls