Small fix for Cexio

[horsecoin]

Changes I made to get Cexio exchange to work. Please Mike take a look-if good pull, else fix!
Thanks!

Example error it was throwing before fixes:

TypeError: Cannot read property 'amount' of undefined

at Manager.getBalance (/home/nick/gekko2/core/portfolioManager.js:108:28)

at bound [as getBalance] (/home/nick/gekko2/node_modules/lodash/dist/lodash.js:729:21)

at act (/home/nick/gekko2/core/portfolioManager.js:130:26)

at bound (/home/nick/gekko2/node_modules/lodash/dist/lodash.js:729:21)

at /home/nick/gekko2/node_modules/async/lib/async.js:232:13

at /home/nick/gekko2/node_modules/async/lib/async.js:142:25

at /home/nick/gekko2/node_modules/async/lib/async.js:229:17

at /home/nick/gekko2/node_modules/async/lib/async.js:556:34

at set (/home/nick/gekko2/core/portfolioManager.js:78:7)

at bound (/home/nick/gekko2/node_modules/lodash/dist/lodash.js:729:21)

[horsecoin]

had issues- back to drawing board