Update coveralls dependencies and service name (#541)

Author: mzjp2

.travis.yml

@@ -49,4 +49,4 @@ script:
   - if [[ $BUILD_DOCS == 'true' ]]; then tox -e docs; fi
 
 after_success:
-  - coveralls
+  - coveralls --service=travis-pro

requirements_dev_optional.txt

@@ -11,8 +11,8 @@ redis==3.3.8
 pymongo==3.9.0
 # optional test requirements
 tox==3.14.0
-coverage==4.5.4
-coveralls==1.8.2
+coverage==5.0.3
+coveralls==1.11.1
 flake8==3.7.8
 pytest-cov==2.7.1
 pytest-doctestplus==0.4.0