PEP8+Better JSON-LD support

* The API has also changed, there are new parameters to send the
context as part of the headers.
* Improved tests
* PEP8 compliance (despite the line about gevent)

plugins/sentiment140/sentiment140.py

@@ -17,7 +17,8 @@ class Sentiment140Plugin(SentimentPlugin):
 
         p = params.get("prefix", None)
         response = Response(prefix=p)
-        polarity_value = self.maxPolarityValue*int(res.json()["data"][0]["polarity"]) * 0.25
+        polarity_value = self.maxPolarityValue*int(res.json()["data"][0]
+                                                   ["polarity"]) * 0.25
         polarity = "marl:Neutral"
         if polarity_value > 50:
             polarity = "marl:Positive"

plugins/sentiment140/sentiment140.senpy

@@ -6,6 +6,7 @@
     "version": "0.1",
     "extra_params": {
         "language": {
+            "@id": "lang_sentiment140",
             "aliases": ["language", "l"],
             "required": false,
             "options": ["es", "en", "auto"]