Merge branch 'master' into 'master'

Update Dockerfile

See merge request !2

Dockerfile

-FROM python:2.7.13
+FROM python:3.6.12
 
 LABEL maintainer "Patrick Chabrier <patrick.chabrier@inrae.fr>"
 
 ENV DEBIAN_FRONTEND noninteractive
 
-RUN pip install git+https://github.com/galaxyproject/planemo.git@0.55.0
+RUN pip install git+https://github.com/galaxyproject/planemo.git@0.74.1
 
 ENV GALAXY_TEST_UPLOAD_ASYNC false
 ENV GALAXY_TEST_DEFAULT_INTERACTOR api