(#72) Add ability to include sources from config

[TheCakeIsNaOH]

Description Of Changes

This adds the --include-configured-sources switch which will append
any sources in the config to manually specified sources (via --source).
It checks if the source already exists before appending, which prevents
duplication when the manually specified sources and the sources from
config are combined.

Motivation and Context

When testing a package locally, it may have depencies that are not installed, and available on a remote repository, like the Community Repository. This allows installation/upgrading of the package without having to specify that remote repository explicitly in --source, assuming it is in the sources configured with the source command.

Testing

Validate that the switch is ignored when using an alternate source:
.\choco.exe install nonexistant-package --source=python --include-configured-sources
Output should include this message: Not including sources from config because python is an alternate source

Validate that config sources are not included when not using switch:
.\choco.exe install nonexistant-package --source .
Output error should specify source as '.', and not include the default community repository.

Validate that config sources are included when using switch:
.\choco.exe install nonexistant-package --source . --include-configured-sources
Output error should specify sources as '.;https://community.chocolatey.org/api/v2/'

Validate that config sources are not duplicated if included both in --source and config:
.\choco.exe install nonexistant-package --source="https://community.chocolatey.org/api/v2/" --include-configured-sources
Output error should specify source as 'https://community.chocolatey.org/api/v2/'

Change Types Made

• Bug fix (non-breaking change)
• Feature / Enhancement (non-breaking change)
• Breaking change (fix or feature that could cause existing functionality to change)

Related Issue

Fixes #72

Change Checklist

• Requires a change to the documentation
• Documentation has been updated
• Tests to cover my changes, have been added
• All new and existing tests passed.
• N/A PowerShell v2 compatibility checked.

[pauby]

The name of the switch --include-machine-sources I don't feel is consistent with other switches. We don't use the word machine in any other switches so it's not intuitive.

The issue talks about --include-default-sources but given the work so make a source a default push source, that may also be confusing.

[TheCakeIsNaOH]

The name of the switch --include-machine-sources I don't feel is consistent with other switches. We don't use the word machine in any other switches so it's not intuitive.

That is what the configured sources are called internally in the code, which is why I picked that.

The issue talks about --include-default-sources but given the work so make a source a default push source, that may also be confusing.

Fair enough, that is pulled from the original issue.

I'm completely open to options for the name of the switch.

[TheCakeIsNaOH]

I've updated the switch name to --include-sources-from-config

[coveralls]

Coverage remained the same at 27.611% when pulling ab36aac on TheCakeIsNaOH:include-machine-sources into 3892cfb on chocolatey:develop.

[gep13]

What about --include-configured-sources for the option name?

[TheCakeIsNaOH]

What about --include-configured-sources for the option name?

Sounds good to me. Should I switch it over to that?

[gep13]

LGTM!

[gep13]

@TheCakeIsNaOH thanks, again, for all your work here! Really appreciate it!