handle DashboardFolder, DocumentFolder, EmailFolder and ReportFolder

[amtrack]

This makes it possible to explicitly deploy folders (e.g. a ReportFolder) which is defined by the the -meta.xml file.

$ force-dev-tool changeset create report-folder ReportFolder/Sales_Marketing_Reports
Manifest:
<?xml version="1.0" encoding="UTF-8"?>
<Package xmlns="http://soap.sforce.com/2006/04/metadata">
    <types>
        <members>Sales_Marketing_Reports</members>
        <name>Report</name>
    </types>
    <version>41.0</version>
</Package>

exported metadata container to config/deployments/report-folder

$ tree config/deployments/report-folder
config/deployments/report-folder
├── package.xml
└── reports
    └── Sales_Marketing_Reports-meta.xml

1 directory, 2 files