Fixes #1294 #181

	name: check-CLA
	on: [pull_request_target]
	jobs:
	check-cla:
	runs-on: ubuntu-latest
	env:
	PR_NUMBER: ${{ github.event.number }}
	steps:
	- name: check-CLA
	run: \|
	import urllib.request
	import json
	import sys
	def jsonRequest(url, data={}):
	req = urllib.request.Request(url,
	headers={'Content-Type': 'application/json'},
	data=json.dumps(data).encode('utf-8') if data else None)
	with urllib.request.urlopen(req) as response:
	return json.loads(response.read().decode('utf-8'))
	prCommits = jsonRequest('https://api.github.com/repos/juce-framework/JUCE/pulls/${{ github.event.number }}/commits')
	allAuthors = [commit[authorType]['login'] for authorType in ['author', 'committer'] for commit in prCommits if commit[authorType]]
	uniqueAuthors = [name for name in list(set(allAuthors)) if name != 'web-flow']
	if (len(uniqueAuthors) == 0):
	print(f'\nNo author or committer user IDs contained within commit information\n\n{prCommits}\n')
	sys.exit(1)
	print(f'Authors: {uniqueAuthors}')
	claResult = jsonRequest('https://cla.juce.com/check', {'logins': uniqueAuthors})
	unsignedLogins = claResult['unsigned']
	if (len(unsignedLogins) != 0):
	print(f'\nThe following GitHub users need to sign the JUCE CLA: {", ".join(unsignedLogins)}\n\nPlease go to https://cla.juce.com to sign the JUCE Contributor Licence Agreement\n')
	sys.exit(1)
	shell: python

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