Update TestGenerateApexDocs regex to fix windows test
Update TestGenerateApexDocs regex to fix windows test

This commit updates the test regex to match either windows or unix file
separators.

The command generated on Windows:
    java -jar c:\users\ieuser\appdata\local\temp\tmp9splyd\apexdoc.jar -s \Users\IEUser\Documents\GitHub\CumulusCI-Test\src\classes -t \Users\IEUser\Documents\GitHub\CumulusCI-Test -p "global;public;private;testmethod;webService"

SalesforceFoundation/CumulusCI,SalesforceFoundation/CumulusCI