Validate your input

[edoput]

This pr adds a command to validate the netjson input after it has been merged with templates and such.

As an example, using the NetJSON found here

netjsonconfig -c example.json -b openwrt -m validate --verbose
netjsonconfig: JSON Schema violation
ValidationError {u'name': u'radio0', u'country': u'en', u'disabled': False, u'phy': u'phy0', u'tx_power': 18, u'channel': 149, u'channel_width': 20} is not valid under any of the given schemas {u'name': u'radio0', u'country': u'en', u'disabled': False, u'phy': u'phy0', u'tx_power': 18, u'channel': 149, u'channel_width': 20} is not valid under any of the given schemas

Failed validating 'oneOf' in schema['properties']['radios']['items']:
    {'oneOf': [{'$ref': '#/definitions/radio_80211gn_settings'},
               {'$ref': '#/definitions/radio_80211an_settings'},
               {'$ref': '#/definitions/radio_80211ac_2ghz_settings'},
               {'$ref': '#/definitions/radio_80211ac_5ghz_settings'},
               {'$ref': '#/definitions/radio_80211bg_settings'},
               {'$ref': '#/definitions/radio_80211a_settings'}],
     'title': 'Radio'}

On instance['radios'][0]:
    {u'channel': 149,
     u'channel_width': 20,
     u'country': u'en',
     u'disabled': False,
     u'name': u'radio0',
     u'phy': u'phy0',
     u'tx_power': 18}

[coveralls]

Coverage decreased (-0.1%) to 99.862% when pulling d111d3d on EdoPut:validate-your-input into 7d84c64 on openwisp:master.

[coveralls]

Coverage decreased (-0.1%) to 99.862% when pulling e4f6431 on EdoPut:validate-your-input into 7d84c64 on openwisp:master.

[coveralls]

Coverage decreased (-0.1%) to 99.862% when pulling 4ff7bfb on EdoPut:validate-your-input into 7d84c64 on openwisp:master.

[coveralls]

Coverage decreased (-0.1%) to 99.862% when pulling 4f517f9 on EdoPut:validate-your-input into 7d84c64 on openwisp:master.

[nemesifier]

Now squash the commits into one, the commit message should be something like:

[module name] Past tense verbe of action performed

Extended descritption

Example:

[bin] Added validate to method options

With this change we can validate NetJSON files via command line.
The patch includes documentation and tests.

[coveralls]

Coverage decreased (-0.1%) to 99.862% when pulling e5b91a1 on EdoPut:validate-your-input into 7d84c64 on openwisp:master.