Upload binaries in a different folder for Bintray

Even when they are linked to different versions, Bintray does not allow
to upload a file with the same name ?!

https://travis-ci.org/jcgay/parallel-git-repo/builds/265907874

    [Bintray Upload] Reading descriptor file: bintray/descriptor.json
    [Bintray Upload] Creating version 'v1.0.1'...
    [Bintray Upload] Bintray response: 201 Created.
    [Bintray Upload] Uploading file 'cross/parallel-git-repo-darwin-amd64' to parallel-git-repo-darwin-amd64
    [Bintray Upload] Bintray response: 409 Conflict. Unable to upload files: An artifact with the path 'parallel-git-repo-darwin-amd64' already exists under another version
    [Bintray Upload] Uploading file 'cross/parallel-git-repo-darwin-amd64.md5' to parallel-git-repo-darwin-amd64.md5
    [Bintray Upload] Bintray response: 409 Conflict. Unable to upload files: An artifact with the path 'parallel-git-repo-darwin-amd64.md5' already exists under another version
    [Bintray Upload] Uploading file 'cross/parallel-git-repo-darwin-amd64.sha256' to parallel-git-repo-darwin-amd64.sha256
    [Bintray Upload] Bintray response: 201 Created. success
    [Bintray Upload] Uploading file 'cross/parallel-git-repo-linux-386' to parallel-git-repo-linux-386
    [Bintray Upload] Bintray response: 409 Conflict. Unable to upload files: An artifact with the path 'parallel-git-repo-linux-386' already exists under another version
    [Bintray Upload] Uploading file 'cross/parallel-git-repo-linux-386.md5' to parallel-git-repo-linux-386.md5
    [Bintray Upload] Bintray response: 409 Conflict. Unable to upload files: An artifact with the path 'parallel-git-repo-linux-386.md5' already exists under another version
    [Bintray Upload] Uploading file 'cross/parallel-git-repo-linux-386.sha256' to parallel-git-repo-linux-386.sha256
    [Bintray Upload] Bintray response: 201 Created. success
    [Bintray Upload] Uploading file 'cross/parallel-git-repo-linux-amd64' to parallel-git-repo-linux-amd64
    [Bintray Upload] Bintray response: 409 Conflict. Unable to upload files: An artifact with the path 'parallel-git-repo-linux-amd64' already exists under another version
    [Bintray Upload] Uploading file 'cross/parallel-git-repo-linux-amd64.md5' to parallel-git-repo-linux-amd64.md5
    [Bintray Upload] Bintray response: 409 Conflict. Unable to upload files: An artifact with the path 'parallel-git-repo-linux-amd64.md5' already exists under another version
    [Bintray Upload] Uploading file 'cross/parallel-git-repo-linux-amd64.sha256' to parallel-git-repo-linux-amd64.sha256
    [Bintray Upload] Bintray response: 201 Created. success
    [Bintray Upload] Uploading file 'cross/parallel-git-repo-windows-amd64' to parallel-git-repo-windows-amd64
    [Bintray Upload] Bintray response: 409 Conflict. Unable to upload files: An artifact with the path 'parallel-git-repo-windows-amd64' already exists under another version
    [Bintray Upload] Uploading file 'cross/parallel-git-repo-windows-amd64.md5' to parallel-git-repo-windows-amd64.md5
    [Bintray Upload] Bintray response: 409 Conflict. Unable to upload files: An artifact with the path 'parallel-git-repo-windows-amd64.md5' already exists under another version
    [Bintray Upload] Uploading file 'cross/parallel-git-repo-windows-amd64.sha256' to parallel-git-repo-windows-amd64.sha256
    [Bintray Upload] Bintray response: 201 Created. success
    [Bintray Upload] Publishing version 'v1.0.1' of package 'parallel-git-repo'...
    [Bintray Upload] Bintray response: 200 OK.

bintray/descriptor.json

@@ -25,7 +25,7 @@
 
     "files":
         [
-        {"includePattern": "cross/(.*)", "uploadPattern": "$1"}
+        {"includePattern": "cross/(.*)", "uploadPattern": "%VERSION%/$1"}
         ],
     "publish": true
 }