Several fixes

* Refactored BaseModel for efficiency
* Added plugin metaclass to keep track of plugin types
* Moved plugins to examples dir (in a previous commit)
* Simplified validation in parse_params
* Added convenience methods to mock requests in tests
* Changed help schema to use `.valid_parameters` instead of `.parameters`,
which was used in results to show parameters provided by the user.
* Improved UI
    * Added basic parameters
    * Fixed bugs in parameter handling
    * Refactored and cleaned code

example-plugins/sleep_plugin/sleep.py

@@ -0,0 +1,14 @@
+from senpy.plugins import AnalysisPlugin
+from time import sleep
+
+
+class SleepPlugin(AnalysisPlugin):
+    def activate(self, *args, **kwargs):
+        sleep(self.timeout)
+
+    def analyse_entry(self, entry, params):
+        sleep(float(params.get("timeout", self.timeout)))
+        yield entry
+
+    def test(self):
+        pass

example-plugins/sleep_plugin/sleep.senpy

@@ -0,0 +1,16 @@
+{
+    "name": "Sleep",
+    "module": "sleep",
+    "description": "I am dummy",
+    "author": "@balkian",
+    "version": "0.1",
+    "timeout": 0.05,
+    "extra_params": {
+        "timeout": {
+            "@id": "timeout_sleep",
+            "aliases": ["timeout", "to"],
+            "required": false,
+            "default": 0
+        }
+     }
+}