Python-engineio-client

(following `engine.io` update)

- [fix] Fixed regression creating connection over https from node (513)
- [fix] Fixed regression creating connection over wss from node (514)
- [feature] Enable definition of timeouts for xhr-polling (456)
- [feature] Added flag forceNode to override the normal behavior of prefering Browser based implementations. (469)
- [feature] add localAddress option (487)
- [chore] update dependencies (516)
- [chore] Speed up lint by avoiding '*_/_.js' matching pattern (517)
- [chore] Bump debug to version 2.3.3 (520)

- [fix] Set accept header to _/_ to support react app proxy (508)
- [fix] remove a workaround for ios (465)
- [fix] onPacket now emits data on 'closing' state as well (484)
- [fix] Obfuscate `ActiveXObject` occurrences (509)
- [docs] Add missing `onlyBinaryUpgrades` option in the docs (510)
- [chore] Add Github issue and PR templates (511)

- [fix] Define "requestsCount" var and "requests" hash unconditionally (490)
- [perf] Add all properties to the socket in the constructor (488)
- [chore] Update zuul browser settings (504)
- [chore] Bump engine.io-parser to 1.3.1 (505)
- [chore] Use more-specific imports for StealJS compatibility (467)

- [fix] Revert "default `rejectUnauthorized` to `true`" (496)
- [fix] Use xhr.responseText if xhr.response is not provided (483)
- [fix] Fix issue with errors during WebSocket creation not being caught (475)
- [style] Add missing semi-colon (501)
- [chore] Add gulp & babel in the build process (455)
- [chore] Add eslint (458)
- [chore] Bump zuul (464)
- [chore] Remove unused submodule (466)
- [chore] Bumping ws to 1.1.1 (478)
- [chore] Update zuul browser settings following EOL notices (486)
- [chore] Bump engine.io-parser (492)
- [chore] Make the build status badge point towards master (497)
- [chore] Bump zuul to 3.11.0 & zuul-ngrok to 4.0.0 (498)
- [chore] Restrict files included in npm package (499)

Testing release