Merge pull request #1 from mailgun/master

Update fork from original
Added whitespace before backslash in cURL command

Ignoring a space before backslash "\" makes cURL read the parameters like this

    -d event='sent'-d event='opened' -d skip=1 -d limit=2

which throws the error __curl: (6) Couldn't resolve host 'event=opened'__
Added whitespace before backslash in cURL command
Added whitespace before backslash in cURL command
Added a backslash to the cURL command
Added a backslash to the cURL command
Added a template variable %recipient_name%
Merge pull request #2 from mailgun/master

Update fork from original
Merge pull request #41 from jesinwp/master

Missing backslashes and whitespaces before them