Create new module to aid in interacting with the RFC repo

[JamesWTruher]

A few functions to help with the RFC repo.
Get-NextRFCNumber will return the next available number for an RFC

NAME
    Get-GitFork

SYNOPSIS
    Get-GitFork [-repoOwner [string]] [-repoName [string]]

    Get-GitFork [-forkurl [string]]]


    -------------------------- EXAMPLE 1 --------------------------

    PS>get-gitfork -repoName PowerShell-RFC | select -first 3

    pushed_at           html_url
    ---------           --------
    4/24/19 10:16:37 PM https://github.com/SydneyhSmith/PowerShell-RFC
    1/16/19 4:34:24 PM  https://github.com/vcgato29/PowerShell-RFC
    11/21/18 6:14:03 PM https://github.com/IISResetMe/PowerShell-RFC


NAME
    Get-LastCommit

SYNOPSIS
    Get the last commit id from a repository


    -------------------------- EXAMPLE 1 --------------------------

    PS>Get-LastCommit -reponame powershell-rfc

    249e8d88eb779a6003fd138609ae94417ae13698



NAME
    Get-MaxRFC

SYNOPSIS
    Get the repo file information for the highest RFC


    -------------------------- EXAMPLE 1 --------------------------

    PS>get-maxrfc

    size  path                                            file_url
    ----  ----                                            --------
    10393 2-Draft-Accepted/RFC0036-AdditionalTelemetry.md https://github.com/PowerShell/PowerShell-RFC/blob/master/2-Draft-Accepted/RFC0036-AdditionalTelemetry.md



NAME
    Get-MaxRFCNumber

SYNOPSIS
    Get the highest RFC number which is actually part of the repo


    -------------------------- EXAMPLE 1 --------------------------

    PS>get-maxrfcnumber

    36



NAME
    Get-PR

SYNOPSIS
    Get the PRs from a repo


    -------------------------- EXAMPLE 1 --------------------------

    PS>Get-PR -state open | select -first 3

    Number Author   Updated          Title
    ------ ------   -------          -----
    9466   RDIL     4/25/19 2:47 PM  Fix gulp in markdown tests
    9460   xtqqczze 4/25/19 4:05 AM  Suppress PossibleIncorrectUsageOfAssignmentOperator rule violation
    9459   xtqqczze 4/24/19 11:48 PM Avoid using Invoke-Expression




NAME
    Get-RepoFileList

SYNOPSIS
    Retrieve the file list from a repository


    -------------------------- EXAMPLE 1 --------------------------

    PS>Get-RepoFileList -repoName "PowerShell-RFC" | Select-Object -First 3

    size path                                            FileUrl
    ---- ----                                            -------
    2498 1-Draft/RFC0003-Lexical-Strict-Mode.md          https://github.com/PowerShell/PowerShell-RFC/blob/master/1-Draft/RFC0003-Lexical-Strict-Mode.md
    6342 1-Draft/RFC0004-PowerShell-Module-Versioning.md https://github.com/PowerShell/PowerShell-RFC/blob/master/1-Draft/RFC0004-PowerShell-Module-Versioning.md

NAME
    Get-RFCPullRequest

SYNOPSIS
    Retrieve pull requestions for the PowerShell-RFC repo


    -------------------------- EXAMPLE 1 --------------------------

    PS>Get-RFCPullRequest -state open | select-object -first 3

    Number Author       Updated          Title
    ------ ------       -------          -----
    167    iSazonov     4/24/19 12:53 PM Enhance some cmdlets with Culture and Comparison parameters
    164    daxian-dbw   4/2/19 7:33 PM   Investigation on supporting module isolation
    163    SydneyhSmith 4/11/19 1:21 AM  Update RFC0004-PowerShell-Module-Versioning.md

[JamesWTruher]

@SteveL-MSFT please take a look, I think I've updated everything