Refactor ssh functionality

[xtrasimplicity]

Refactoring the SSH functionality into a wrapper around net/ssh, so that we can replace net/ssh without any major issues (if required) and simplify the core test suite and codebase.

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This change is 

[coveralls]

Pull Request Test Coverage Report for Build 40

• 189 of 229 (82.53%) changed or added relevant lines in 10 files are covered.
• 34 unchanged lines in 3 files lost coverage.
• Overall coverage decreased (-15.6%) to 84.355%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
test/shared/matchers/duck_type_including.rb	12	14	85.71%
lib/shell_strike/ssh/command_result.rb	3	5	60.0%
lib/shell_strike/ssh.rb	11	47	23.4%

Files with Coverage Reduction	New Missed Lines	%
spec/support/helpers/chain_helpers.rb	7	41.67%
lib/shell_strike/result.rb	8	42.86%
spec/support/matchers/result.rb	19	9.52%

Totals
Change from base Build 32:	-15.6%
Covered Lines:	399
Relevant Lines:	473

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💛 - Coveralls

[coveralls]

Pull Request Test Coverage Report for Build 33

• 85 of 110 (77.27%) changed or added relevant lines in 5 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage decreased (-6.0%) to 94.033%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
spec/shell_strike/ssh_spec.rb	67	68	98.53%
lib/shell_strike/ssh/command_result.rb	3	7	42.86%
lib/shell_strike.rb	2	6	33.33%
lib/shell_strike/ssh.rb	11	27	40.74%

Totals
Change from base Build 32:	-6.0%
Covered Lines:	394
Relevant Lines:	419

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💛 - Coveralls

[coveralls]

Pull Request Test Coverage Report for Build 33

• 85 of 110 (77.27%) changed or added relevant lines in 5 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage decreased (-6.0%) to 94.033%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
spec/shell_strike/ssh_spec.rb	67	68	98.53%
lib/shell_strike/ssh/command_result.rb	3	7	42.86%
lib/shell_strike.rb	2	6	33.33%
lib/shell_strike/ssh.rb	11	27	40.74%

Totals
Change from base Build 32:	-6.0%
Covered Lines:	394
Relevant Lines:	419

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💛 - Coveralls