Delete travis workaround as problem seems to be fixed

Author: SabineHaas

.travis.yml

@@ -13,7 +13,6 @@ matrix:
 #  - sudo apt-get install coinor-cbc
 
 install:
-  - if [[ $TRAVIS_PYTHON_VERSION == "3.7" ]]; then sudo apt-get install libhdf5-dev; fi
   - pip install .
   - pip install coveralls sphinx nbformat pytest-cov jupyter