Can't upload file with content

[MrVine]

Hello Collaborators,
during testing current version of gowebdav I notice that client's method WriteStream does not set request body even if body should be set for current request (for example during uploading non-empty file via gowebdav.exe -X PUT /my_folder/file.txt file.txt). Also, @chuckwagoncomputing face with this problem too, but he used propfind request instead.

Software

• OS: Windows 10 x64
• Golang: 1.10
• Version: latest commit in master is 008b27e

To Reproduce

1. build gowebdav/cmd/gowebdav with go build to get gowebdav.exe
2. set following environment's variables:
   1. ROOT -- WebDav Server's URL
   2. USER -- WebDav Server's username
   3. PASSWORD -- WebDav Server's password
3. suppose your WebDav Server's folder is my_folder, and your local file to upload located near gowebdav.exe, named file.txt and has some text (so actually file's size is not zero).
4. run following command: gowebdav.exe -X PUT /my_folder/file.txt file.txt
5. go to your WebDav Server via any other interface (putty, web browser etc), and you will see that file is exist but file's size is zero

Expected
Uploaded file contains body

Actually
Uploaded file does not contains body

[MrVine]

This bug was fixed by pull-request #21