Running your config.yml through yamllint, produced the following:
1:1 warning missing document start "---" (document-start)
13:3 error duplication of key "build" in mapping (key-duplicates)
25:19 error syntax error: mapping values are not allowed here
When I add colons to the entry on lines 25 and 28:
You simply have an incorrect yaml syntax in your workflows jobs list.
From what I could very quickly understand on circleCI's documentation, jobs names are accepted as a shorthand if you don't define any parameters. If you have parameters, the list element is a hashmap with top element being the job name. In your specific case, this should give (note the ...