Update .travis.yml with new conda activate

Author: vuillaut

.travis.yml

@@ -24,7 +24,7 @@ before_install:
         wget https://repo.continuum.io/miniconda/Miniconda3-latest-MacOSX-x86_64.sh -O miniconda.sh;
       fi
     - bash miniconda.sh -b -p $HOME/miniconda
-    - export PATH="$HOME/miniconda/bin:$PATH"
+    - . $HOME/miniconda/etc/profile.d/conda.sh
     - hash -r
     - conda config --set always_yes yes --set changeps1 no
     - conda update -q conda  # get latest conda version
@@ -34,9 +34,9 @@ before_install:
 
 install:
     - conda env create --file environment.yml
-    - source activate cta-benchmarks
+    - conda activate cta-benchmarks
 
 after_script:
-    - source deactivate
+    - conda deactivate
 
 #after_success: