setup.py: fix py3sensors installation and conditionalize scandir dependency

- scandir package is only needed for Python < 3.5.
- the name of extras are now lower case (easier to type/read).

Note: setuptools >= 18.0 is required.

README.rst

@@ -55,7 +55,7 @@ Optional dependencies:
 - ``bottle`` (for Web server mode)
 - ``cassandra-driver`` (for the Cassandra export module)
 - ``couchdb`` (for the CouchDB export module)
-- ``docker-py`` (for the Docker monitoring support) [Linux-only]
+- ``docker`` (for the Docker monitoring support) [Linux-only]
 - ``elasticsearch`` (for the Elastic Search export module)
 - ``hddtemp`` (for HDD temperature monitoring support) [Linux-only]
 - ``influxdb`` (for the InfluxDB export module)
@@ -133,14 +133,14 @@ features (like the Web interface, exports modules, sensors...):
 
 .. code-block:: console
 
-    pip install glances[ACTION,BATINFO,BROWSER,CPUINFO,CHART,DOCKER,EXPORT,FOLDERS,GPU,IP,RAID,SNMP,WEB,WIFI]
+    pip install glances[action,batinfo,browser,cpuinfo,chart,docker,export,folders,gpu,ip,raid,snmp,web,wifi]
 
 To upgrade Glances to the latest version:
 
 .. code-block:: console
 
     pip install --upgrade glances
-    pip install --upgrade glances[ACTION,BATINFO,BROWSER,CPUINFO,CHART,DOCKER,EXPORT,FOLDERS,GPU,IP,RAID,SNMP,WEB,WIFI]
+    pip install --upgrade glances[...]
 
 If you need to install Glances in a specific user location, use:
 

setup.py

@@ -78,21 +78,22 @@ setup(
     keywords="cli curses monitoring system",
     install_requires=get_install_requires(),
     extras_require={
-        'ACTION': ['pystache'],
-        'BATINFO': ['batinfo'],
-        'BROWSER': ['zeroconf>=0.17'],
-        'CPUINFO': ['py-cpuinfo'],
-        'CHART': ['matplotlib'],
-        'DOCKER': ['docker>=2.0.2'],
-        'EXPORT': ['bernhard', 'cassandra-driver', 'couchdb', 'elasticsearch', 'influxdb>=1.0.0', 'pika', 'potsdb', 'pyzmq', 'statsd'],
-        'FOLDERS': ['scandir'],
-        'GPU': ['nvidia-ml-py'],
-        'IP': ['netifaces'],
-        'RAID': ['pymdstat'],
-        'SENSORS': ['py3sensors'],
-        'SNMP': ['pysnmp'],
-        'WEB': ['bottle', 'requests'],
-        'WIFI': ['wifi']
+        'action': ['pystache'],
+        'batinfo': ['batinfo'],
+        'browser': ['zeroconf>=0.17'],
+        'cpuinfo': ['py-cpuinfo'],
+        'chart': ['matplotlib'],
+        'docker': ['docker>=2.0.0'],
+        'export': ['bernhard', 'cassandra-driver', 'couchdb', 'elasticsearch',
+                   'influxdb>=1.0.0', 'pika', 'potsdb', 'pyzmq', 'statsd'],
+        'folders:python_version<"3.5"': ['scandir'],
+        'gpu': ['nvidia-ml-py'],
+        'ip': ['netifaces'],
+        'raid': ['pymdstat'],
+        'sensors': ['https://bitbucket.org/gleb_zhulik/py3sensors/get/tip.zip'],
+        'snmp': ['pysnmp'],
+        'web': ['bottle', 'requests'],
+        'wifi': ['wifi']
     },
     packages=['glances'],
     include_package_data=True,