Misc dependencies and mock fixes.

- `iputils` should be an explicit system dependency for `ping`.
  Some minimal systems (like some Docker images) may not have the `ping`
  command installed out of the box.

- `hid` and `marshmallow_dataclass` should be among the auto-mocked
  modules.

.drone.yml

@@ -113,8 +113,8 @@ steps:
 
   commands:
     - echo "Installing required build dependencies"
-    - apk add --update --no-cache make py3-sphinx py3-myst-parser py3-pip py3-paho-mqtt $(cat platypush/install/requirements/alpine.txt)
-    - pip install -U hid sphinx-rtd-theme sphinx-book-theme
+    - apk add --update --no-cache make py3-sphinx py3-myst-parser py3-pip $(cat platypush/install/requirements/alpine.txt)
+    - pip install -U sphinx-rtd-theme sphinx-book-theme
     - pip install .
     - mkdir -p /docs/current
     - export APPDIR=$PWD

platypush/backend/ping/manifest.yaml

@@ -3,6 +3,12 @@ manifest:
     platypush.message.event.ping.HostDownEvent: if a host stops responding ping requests
     platypush.message.event.ping.HostUpEvent: if a host starts responding ping requests
   install:
-    pip: []
+    apt:
+      - iputils-ping
+    dnf:
+      - iputils
+    pacman:
+      - iputils
+
   package: platypush.backend.ping
   type: backend

platypush/plugins/ping/manifest.yaml

@@ -1,6 +1,12 @@
 manifest:
   events: {}
   install:
-    pip: []
+    apt:
+      - iputils-ping
+    dnf:
+      - iputils
+    pacman:
+      - iputils
+
   package: platypush.plugins.ping
   type: plugin

platypush/utils/mock/modules.py

@@ -45,6 +45,7 @@ mock_imports = [
     "graphyte",
     "grpc",
     "gunicorn",
+    "hid",
     "httplib2",
     "icalendar",
     "imapclient",
@@ -60,6 +61,7 @@ mock_imports = [
     "keras",
     "linode_api4",
     "luma",
+    "marshmallow_dataclass",
     "mpd",
     "ndef",
     "nfc",