install anaconda by default

defaults/main.yml

@@ -1,4 +1,4 @@
 ---
-conda_directory: /opt/conda
-conda_installer_url: https://repo.continuum.io/miniconda/Miniconda3-4.5.11-Linux-x86_64.sh
-conda_installer_checksum: sha256:ea4594241e13a2671c5b158b3b813f0794fe58d514795fbf72a1aad24db918cf
+conda_directory: /opt/anaconda
+conda_installer_url: https://repo.anaconda.com/archive/Anaconda3-5.3.0-Linux-x86_64.sh
+conda_installer_checksum: sha256:cfbf5fe70dd1b797ec677e63c61f8efc92dad930fd1c94d60390bb07fdc09959