Link enabling registrations and invites in settings

Closes #97 (closed)

src/views/settings/components/inputComponents/RegInvitesInput.vue

+<template>
+  <el-switch
+    :value="data[setting.key]"
+    :data-search="setting.key"
+    class="switch-input"
+    @change="updateSetting($event, settingGroup.group, settingGroup.key, setting.key, setting.type)"/>
+</template>
+
+<script>
+export default {
+  name: 'RegInvitesInput',
+  props: {
+    data: {
+      type: [Object, Array],
+      default: function() {
+        return {}
+      }
+    },
+    setting: {
+      type: Object,
+      default: function() {
+        return {}
+      }
+    },
+    settingGroup: {
+      type: Object,
+      default: function() {
+        return {}
+      }
+    }
+  },
+  methods: {
+    updateSetting(value, group, key, input, type) {
+      const registrationsOpen = this.$store.state.settings.settings[group][key][':registrations_open']
+      const invitesEnabled = this.$store.state.settings.settings[group][key][':invites_enabled']
+      if (input === ':registrations_open' && value && invitesEnabled) {
+        this.$confirm(
+          'Enabling this setting requires invites to be disabled. Are you sure you want to open registrations?',
+          'Warning',
+          { confirmButtonText: 'OK',
+            cancelButtonText: 'Cancel',
+            type: 'warning'
+          }).then(() => {
+          this.$store.dispatch('UpdateSettings', { group, key, input, value, type })
+          this.$store.dispatch('UpdateSettings', { group, key, input: ':invites_enabled', value: false, type })
+          this.$store.dispatch('UpdateState', { group, key, input, value })
+          this.$store.dispatch('UpdateState', { group, key, input: ':invites_enabled', value: false })
+        })
+      } else if (input === ':invites_enabled' && value && registrationsOpen) {
+        this.$confirm(
+          'Enabling this setting requires registrations to be disabled. Are you sure you want to enable invitations?',
+          'Warning',
+          { confirmButtonText: 'OK',
+            cancelButtonText: 'Cancel',
+            type: 'warning'
+          }).then(() => {
+          this.$store.dispatch('UpdateSettings', { group, key, input, value, type })
+          this.$store.dispatch('UpdateSettings', { group, key, input: ':registrations_open', value: false, type })
+          this.$store.dispatch('UpdateState', { group, key, input, value })
+          this.$store.dispatch('UpdateState', { group, key, input: ':registrations_open', value: false })
+        })
+      } else {
+        this.$store.dispatch('UpdateSettings', { group, key, input, value, type })
+        this.$store.dispatch('UpdateState', { group, key, input, value })
+      }
+    }
+  }
+}
+</script>
+
+<style rel='stylesheet/scss' lang='scss'>
+@import '../../styles/main';
+@include settings
+</style>