Bump Cake script dependencies

Use https://github.com/dependabot/dependabot-core/pull/1848 dry run to identify outdated dependencies in Cake scripts:

/:

[dependabot-core-dev] ~/dependabot-core $ bin/dry-run.rb --dir / cake cake-build/cake
warning: parser/current is loading parser/ruby26, which recognizes
warning: 2.6.6-compliant syntax, but you are running 2.6.5.
warning: please see https://github.com/whitequark/parser#compatibility-with-ruby-mri.
=> fetching dependency files
=> dumping fetched dependency files: ./dry-run/cake-build/cake/
=> parsing dependency files
=> updating 11 dependencies

=== Cake.DotNetTool.Module (0.4.0)
 => checking for updates
 => latest version from registry is 0.4.0
 => latest resolvable version is 0.4.0
    (no update needed)

=== Cake.Coveralls (0.10.1)
 => checking for updates
 => latest version from registry is 0.10.2
 => latest resolvable version is 0.10.2
 => requirements to unlock: own
 => requirements update strategy: 
 => updating Cake.Coveralls from 0.10.1 to 0.10.2

    ± build.cake
    ~~~
    5c5
    < #addin "nuget:https://api.nuget.org/v3/index.json?package=Cake.Coveralls&version=0.10.1"
    ---
    > #addin "nuget:https://api.nuget.org/v3/index.json?package=Cake.Coveralls&version=0.10.2"
    ~~~

=== Cake.Twitter (0.10.1)
 => checking for updates
 => latest version from registry is 0.10.1
 => latest resolvable version is 0.10.1
    (no update needed)

=== Cake.Gitter (0.11.1)
 => checking for updates
 => latest version from registry is 0.11.1
 => latest resolvable version is 0.11.1
    (no update needed)

=== coveralls.io (1.4.2)
 => checking for updates
 => latest version from registry is 1.4.2
 => latest resolvable version is 1.4.2
    (no update needed)

=== OpenCover (4.7.922)
 => checking for updates
 => latest version from registry is 4.7.922
 => latest resolvable version is 4.7.922
    (no update needed)

=== ReportGenerator (4.5.8)
 => checking for updates
 => latest version from registry is 4.7.1
 => latest resolvable version is 4.7.1
 => requirements to unlock: own
 => requirements update strategy: 
 => updating ReportGenerator from 4.5.8 to 4.7.1

    ± build.cake
    ~~~
    12c12
    < #tool "nuget:https://api.nuget.org/v3/index.json?package=ReportGenerator&version=4.5.8"
    ---
    > #tool "nuget:https://api.nuget.org/v3/index.json?package=ReportGenerator&version=4.7.1"
    ~~~

=== nuget.commandline (5.5.1)
 => checking for updates
 => latest version from registry is 5.7.0
 => latest resolvable version is 5.7.0
 => requirements to unlock: own
 => requirements update strategy: 
 => updating nuget.commandline from 5.5.1 to 5.7.0

    ± build.cake
    ~~~
    13c13
    < #tool "nuget:https://api.nuget.org/v3/index.json?package=nuget.commandline&version=5.5.1"
    ---
    > #tool "nuget:https://api.nuget.org/v3/index.json?package=nuget.commandline&version=5.7.0"
    ~~~

=== GitVersion.Tool (5.1.2)
 => checking for updates
 => latest version from registry is 5.5.0
 => latest resolvable version is 5.5.0
 => requirements to unlock: own
 => requirements update strategy: 
 => updating GitVersion.Tool from 5.1.2 to 5.5.0

    ± build.cake
    ~~~
    16c16
    < #tool "dotnet:https://api.nuget.org/v3/index.json?package=GitVersion.Tool&version=5.1.2"
    ---
    > #tool "dotnet:https://api.nuget.org/v3/index.json?package=GitVersion.Tool&version=5.5.0"
    ~~~

=== SignClient (1.2.109)
 => checking for updates
 => latest version from registry is 1.2.109
 => latest resolvable version is 1.2.109
    (no update needed)

=== GitReleaseManager.Tool (0.11.0)
 => checking for updates
 => latest version from registry is 0.11.0
 => latest resolvable version is 0.11.0
    (no update needed)

/tests/integration:

[dependabot-core-dev] ~/dependabot-core $ bin/dry-run.rb --dir /tests/integration cake cake-build/cake
warning: parser/current is loading parser/ruby26, which recognizes
warning: 2.6.6-compliant syntax, but you are running 2.6.5.
warning: please see https://github.com/whitequark/parser#compatibility-with-ruby-mri.
=> fetching dependency files
=> dumping fetched dependency files: ./dry-run/cake-build/cake/tests/integration
=> parsing dependency files
=> updating 3 dependencies

=== xunit.assert (2.4.1)
 => checking for updates
 => latest version from registry is 2.4.1
 => latest resolvable version is 2.4.1
    (no update needed)

=== nuget.commandline (5.5.1)
 => checking for updates
 => latest version from registry is 5.7.0
 => latest resolvable version is 5.7.0
 => requirements to unlock: own
 => requirements update strategy: 
 => updating nuget.commandline from 5.5.1 to 5.7.0

    ± Cake.Common/Tools/NuGet/NuGetAliases.cake
    ~~~
    1c1
    < #tool "nuget:https://api.nuget.org/v3/index.json?package=nuget.commandline&version=5.5.1"
    ---
    > #tool "nuget:https://api.nuget.org/v3/index.json?package=nuget.commandline&version=5.7.0"
    ~~~

=== Cake.Kudu.Client (0.9.0)
 => checking for updates
 => latest version from registry is 0.9.0
 => latest resolvable version is 0.9.0
    (no update needed)

[gitfool]

@nils-a yeah, on GitLab we schedule a modified dependabot/dependabot-script in a Docker container.

[devlead]

Well, “official” dependabot support would be awesome though.