Applying black formatting

- Fixing flake8 configuration to agree with black
- Adding black validation check to github actions

examples/addressbook.py

@@ -7,26 +7,26 @@ import addressbook_capnp
 
 def writeAddressBook(file):
     addresses = addressbook_capnp.AddressBook.new_message()
-    people = addresses.init('people', 2)
+    people = addresses.init("people", 2)
 
     alice = people[0]
     alice.id = 123
-    alice.name = 'Alice'
-    alice.email = 'alice@example.com'
-    alicePhones = alice.init('phones', 1)
+    alice.name = "Alice"
+    alice.email = "alice@example.com"
+    alicePhones = alice.init("phones", 1)
     alicePhones[0].number = "555-1212"
-    alicePhones[0].type = 'mobile'
+    alicePhones[0].type = "mobile"
     alice.employment.school = "MIT"
 
     bob = people[1]
     bob.id = 456
-    bob.name = 'Bob'
-    bob.email = 'bob@example.com'
-    bobPhones = bob.init('phones', 2)
+    bob.name = "Bob"
+    bob.email = "bob@example.com"
+    bobPhones = bob.init("phones", 2)
     bobPhones[0].number = "555-4567"
-    bobPhones[0].type = 'home'
+    bobPhones[0].type = "home"
     bobPhones[1].number = "555-7654"
-    bobPhones[1].type = 'work'
+    bobPhones[1].type = "work"
     bob.employment.unemployed = None
 
     addresses.write(file)
@@ -36,27 +36,27 @@ def printAddressBook(file):
     addresses = addressbook_capnp.AddressBook.read(file)
 
     for person in addresses.people:
-        print(person.name, ':', person.email)
+        print(person.name, ":", person.email)
         for phone in person.phones:
-            print(phone.type, ':', phone.number)
+            print(phone.type, ":", phone.number)
 
         which = person.employment.which()
         print(which)
 
-        if which == 'unemployed':
-            print('unemployed')
-        elif which == 'employer':
-            print('employer:', person.employment.employer)
-        elif which == 'school':
-            print('student at:', person.employment.school)
-        elif which == 'selfEmployed':
-            print('self employed')
+        if which == "unemployed":
+            print("unemployed")
+        elif which == "employer":
+            print("employer:", person.employment.employer)
+        elif which == "school":
+            print("student at:", person.employment.school)
+        elif which == "selfEmployed":
+            print("self employed")
         print()
 
 
-if __name__ == '__main__':
-    f = open('example', 'w')
+if __name__ == "__main__":
+    f = open("example", "w")
     writeAddressBook(f)
 
-    f = open('example', 'r')
+    f = open("example", "r")
     printAddressBook(f)