sync-template.sh script does not create pull request

[i386x]

I just run ./sync-template.sh -r kernel_settings -t {{token}} and I don't see anything in https://github.com/linux-system-roles/kernel_settings/pulls. By investigating the script's output, I found

{
  "message": "Problems parsing JSON",
  "documentation_url": "https://docs.github.com/rest/reference/pulls#create-a-pull-request"
}

This is related to curl command, which was run as

curl -u 'systemroller:{{token}}' -X POST -d '{"title":"Synchronize files from linux-system-roles/template",
"base":"master",
"head":"lsr-template-sync",
"body":"This PR propagates files from [linux-system-roles/template](https://github.com/linux-system-roles/template) which should be in sync across [linux-system-roles](https://github.com/linux-system-roles) repos. In case of changing affected files via pushing to this PR, please do not forget also to push the changes to [linux-system-roles/template](https://github.com/linux-system-roles/template) repo.

Revision: [`448ff39c16f171b7f09ff5a21e62340add304d55`](https://github.com/linux-system-roles/template/tree/448ff39c16f171b7f09ff5a21e62340add304d55)

CC: @i386x, @pcahyna, @richm"}' 'https://api.github.com/repos/linux-system-roles/kernel_settings/pulls'

curl command above exits with 0, so the script behaves like everything have been ok.

Observe that commit linux-system-roles/kernel_settings@54d04c1 has been pushed to lsr-template-sync branch successfully.

[richm]

Hmm - seems that JSON does not like the newline characters in the body of the PR message:

{"title":"Synchronize files from linux-system-roles/template",
"base":"master",
"head":"lsr-template-sync",
"body":"This PR propagates files from [linux-system-roles/template](https://gith
ub.com/linux-system-roles/template) which should be in sync across [linux-system
-roles](https://github.com/linux-system-roles) repos. In case of changing affect
ed files via pushing to this PR, please do not forget also to push the changes t
o [linux-system-roles/template](https://github.com/linux-system-roles/template) 
repo.

Revision: [`448ff39c16f171b7f09ff5a21e62340add304d55`](https://github.com/linux-
system-roles/template/tree/448ff39c16f171b7f09ff5a21e62340add304d55)

CC: @i386x, @pcahyna, @richm"}

feed this to jq:

parse error: Invalid string: control characters from U+0000 through U+001F must be escaped at line 8, column 29

remove the newlines from the "body" field:

{"title":"Synchronize files from linux-system-roles/template",
"base":"master",
"head":"lsr-template-sync",
"body":"This PR propagates files from [linux-system-roles/template](https://gith
ub.com/linux-system-roles/template) which should be in sync across [linux-system
-roles](https://github.com/linux-system-roles) repos. In case of changing affect
ed files via pushing to this PR, please do not forget also to push the changes t
o [linux-system-roles/template](https://github.com/linux-system-roles/template) 
repo. Revision: [`448ff39c16f171b7f09ff5a21e62340add304d55`](https://github.com/
linux-system-roles/template/tree/448ff39c16f171b7f09ff5a21e62340add304d55) CC: @
i386x, @pcahyna, @richm"}

feed this to jq

{
  "title": "Synchronize files from linux-system-roles/template",
  "base": "master",
  "head": "lsr-template-sync",
  "body": "This PR propagates files from [linux-system-roles/template](https://github.com/linux-system-roles/template) which should be in sync across [linux-system-roles](https://github.com/linux-system-roles) repos. In case of changing affected files via pushing to this PR, please do not forget also to push the changes to [linux-system-roles/template](https://github.com/linux-system-roles/template) repo. Revision: [`448ff39c16f171b7f09ff5a21e62340add304d55`](https://github.com/linux-system-roles/template/tree/448ff39c16f171b7f09ff5a21e62340add304d55) CC: @i386x, @pcahyna, @richm"
}

I probably broke this when I added support for hub to the sync script. That is, I probably broke the newline escaping.

[i386x]

Bash probably transforms escaped \n to real \n when payload string was passed to submit_pr. That's why I don't like strings in Bash. We need to setup unit tests and CI for it with curl, git, and hub mocked.

[richm]

obsolete since we use tox-lsr now