fix(record): fix broken JSONP

It's not necessary to encode the values manually
fix(loader): always pass in an array
test(e2e): add multiple integration tests that send data

event uses trackEvent to send data
pageview uses trackPageview to send data
request uses addRecord to send data as the browser default
jsonp uses addRecord to send data as JSONP
loader checks that the JS snippet will load the library and then send data
slow loader checks that the JS snippet will load the library with a delay and then send data
chore(cleanup): remove unused files
test(task): add e2e task to gulpfile