rename `apiBaseUrl` variable to `baseUrl`
rename `apiBaseUrl` variable to `baseUrl`

Mendeley/mendeley-javascript-sdk,charliehw/mendeley-javascript-sdk,paulwib/mendeley-javascript-sdk,customcommander/mendeley-javascript-sdk,Alex-Radu/mendeley-javascript-sdk,massa84/mendeley-javascript-sdk,customcommander/mendeley-javascript-sdk,charliehw/mendeley-javascript-sdk