fixed
fixed groupIds
Merge branch 'develop'

Conflicts:
	README.md
Merge branch 'develop'
Merge branch 'develop'
Merge branch 'develop'
Merge branch 'develop'
added .travis.yml
Merge branch 'develop'

Conflicts:
	.travis.yml
Merge branch 'develop'
updated ci URL
added auto-header to Maven build
issue # 154, added null check and throw ExchangeException
moved setting of tickerRequestTimeStamp
new blockchain module
added RestJsonException to interface methods
rescu version update
Added sample JSON user transaction file
User transactions JSON unmarshalling test
Added order_id and btc_usd (price) field