Use the mining effect

This effect is only used by mining drones, and it's not been
implemented.

See #762 for more info

eos/effects/mining.py

@@ -0,0 +1,15 @@
+# miningDroneOperationMiningAmountBonusPostPercentMiningDroneAmountPercentChar
+#
+# Used by:
+# Mining Drones
+
+type = "passive"
+def handler(fit, container, context):
+    miningDroneAmountPercent = container.getModifiedItemAttr("miningDroneAmountPercent")
+    if (miningDroneAmountPercent is None) or (miningDroneAmountPercent == 0):
+        miningDroneAmountPercent = 1
+    else:
+        miningDroneAmountPercent = miningDroneAmountPercent/100
+
+    fit.drones.filteredItemMultiply(lambda drone: drone.item.group.name == "Mining Drone",
+                                 "miningAmount", miningDroneAmountPercent)