streamchain

-Rename example to 'attributes_to_state' avoiding 'chaincode_example_XX'
 pattern.
-Rename ambiguous functions "query" and "invoke" to "read" and "submit"
 respectively.
-Fix a compilation error.

Why:
Fixes #2235
https://github.com/hyperledger/fabric/issues/2235



Checklist:
X I have added a Signed-off-by.
X This change requires no new documentation.
X This change requires no new tests.
X I have run golint and have fixed valid warnings in code I have added
  or modified.

Change-Id: Ib15f49d91620ec633019115f81298e95d3473928
Signed-off-by: agaragiola <garagiol@ar.ibm.com>