Add create_login_profile for iam service

moto/iam/models.py

@@ -128,6 +128,7 @@ class User(object):
 
         self.policies = {}
         self.access_keys = []
+        self.password = None
 
     def get_policy(self, policy_name):
         policy_json = None
@@ -270,6 +271,16 @@ class IAMBackend(BaseBackend):
 
         return user
 
+    def create_login_profile(self, user_name, password):
+        if not user_name in self.users:
+            raise BotoServerError(404, 'Not Found')
+
+        # This does not currently deal with PasswordPolicyViolation.
+        user = self.users[user_name]
+        if user.password:
+            raise BotoServerError(409, 'Conflict')
+        user.password = password
+
     def add_user_to_group(self, group_name, user_name):
         group = None
         user = None