add tests

I'm adding a revocation test on wot pallet because it is only present in identity pallet and thus does not handle wot-related limitations.

Also adding identity validation cucumber test.

end2end-tests/cucumber-features/identity_creation.feature

@@ -5,11 +5,24 @@ Feature: Identity creation
     # - account creation fees (3 ĞD) 
     # - existential deposit (2 ĞD)
     # - transaction fees (below 1 ĞD)
-    When alice sends 6 ĞD to ferdie
+    When alice sends 6 ĞD to dave
+    When alice sends 6 ĞD to eve
     # alice last certification is counted from block zero
-    # then next cert can be done after cert_period
+    # then next cert can be done after cert_period, which is 15
     When 15 block later
-    When alice creates identity for ferdie
-    Then ferdie identity should be created
-    When ferdie confirms his identity with pseudo "Ferdie"
-    Then ferdie identity should be confirmed 
+    When alice creates identity for dave
+    Then dave identity should be created
+    Then dave should be certified by alice
+    When dave confirms his identity with pseudo "dave"
+    Then dave identity should be confirmed
+    When 3 block later
+    When bob certifies dave
+    When charlie certifies dave
+    Then dave should be certified by bob
+    Then dave should be certified by charlie
+    When 3 block later
+    # eve is not member, but has enough ĞD to pay extrinsic fees
+    # I don't understand why she can not validate dave's identity 
+    # When eve validates dave identity
+    When alice validates dave identity
+    Then dave identity should be validated