Remove Python 3.4 support (jupyter-client needs at least 3.5)

Author: martinRenou

.travis.yml

@@ -4,7 +4,6 @@ os:
  - osx
 env:
  matrix:
-  - PYTHON_VERSION=3.4
   - PYTHON_VERSION=3.5
   - PYTHON_VERSION=3.6
   - PYTHON_VERSION=3.7

setup.py

@@ -22,7 +22,7 @@
 name = 'ipycanvas'
 
 # Ensure a valid python version
-ensure_python('>=3.4')
+ensure_python('>=3.5')
 
 # Get our version
 version = get_version(pjoin(name, '_version.py'))
@@ -78,7 +78,6 @@
         'License :: OSI Approved :: BSD License',
         'Programming Language :: Python',
         'Programming Language :: Python :: 3',
-        'Programming Language :: Python :: 3.4',
         'Programming Language :: Python :: 3.5',
         'Programming Language :: Python :: 3.6',
         'Programming Language :: Python :: 3.7',