Ensure all operations are done in order

[CatturaGreg]

Previous merges left this plugin in a state where operations were being done in an incorrect order causing the package to not be built. In summary,

• fs.outputFile creates parent directories if they do not exist, so calling fs.mkdir afterwards throws an EEXIST error. Solved by creating the script files after creating the directory.
• Somehow, the dpkg-deb command was being called before the control file was written, causing it to fail.
• callback was not being called after successful dpkg-deb run, causing gulp to complain that the plugin did not complete.

From my tests the plugin should run correctly after this change.

[stpettersens]

Will merge these changes from your fork.

[stpettersens]

Thank you and Merry Christmas 🎄 ⛄ ❄️, @CatturaGreg.
Please find latest [email protected] package on NPM.

[haslinghuis]

Confirm this solves:

[00:21:12] Error in plugin 'gulp-debian'
Message:
    EEXIST: file already exists, mkdir './release//betaflight-configurator_10.9.0_amd64/DEBIAN'
Details:
    errno: -17
    code: EEXIST
    syscall: mkdir
    path: ./release//betaflight-configurator_10.9.0_amd64/DEBIAN
    domainEmitter: [object Object]
    domainThrown: false
[00:21:12] 'release' errored after 9.27 s

betaflight/betaflight-configurator#3155