Feature/sp call limits (#63)

* add api for setting/querying call limits by account and sp

* update an account or sp limit if one exists rather than creating a new one

lib/models/account-limits.js

@@ -0,0 +1,33 @@
+const Model = require('./model');
+
+class AccountLimits extends Model {
+  constructor() {
+    super();
+  }
+}
+
+AccountLimits.table = 'account_limits';
+AccountLimits.fields = [
+  {
+    name: 'account_limits_sid',
+    type: 'string',
+    primaryKey: true
+  },
+  {
+    name: 'account_sid',
+    type: 'string',
+    required: true
+  },
+  {
+    name: 'category',
+    type: 'string',
+    required: true
+  },
+  {
+    name: 'quantity',
+    type: 'number',
+    required: true
+  }
+];
+
+module.exports = AccountLimits;

lib/models/service-provider-limits.js

@@ -0,0 +1,33 @@
+const Model = require('./model');
+
+class ServiceProviderLimits extends Model {
+  constructor() {
+    super();
+  }
+}
+
+ServiceProviderLimits.table = 'service_provider_limits';
+ServiceProviderLimits.fields = [
+  {
+    name: 'service_provider_limits_sid',
+    type: 'string',
+    primaryKey: true
+  },
+  {
+    name: 'service_provider_sid',
+    type: 'string',
+    required: true
+  },
+  {
+    name: 'category',
+    type: 'string',
+    required: true
+  },
+  {
+    name: 'quantity',
+    type: 'number',
+    required: true
+  }
+];
+
+module.exports = ServiceProviderLimits;