Fix a whole bunch of eslint errors

These apparently were silent until 92c532d mass-upgraded deps.
Apparently eslint returned status 0 despite errors before and now
returns 1.

Most of these were handled by its "--fix" option; I manually took care
of the remaining two:

/Users/slamb/git/moonfire-nvr/ui-src/lib/views/RecordingsView.js
  140:1  error  This line has a length of 82. Maximum allowed is 80  max-len

/Users/slamb/git/moonfire-nvr/ui-src/lib/views/StreamSelectorView.js
  72:1  error  This line has a length of 82. Maximum allowed is 80  max-len

ui-src/lib/models/CalendarTSRange.js

@@ -138,9 +138,9 @@ export default class CalendarTSRange {
    * @return {Range90k} Range object or null if don't have start and end
    */
   range90k() {
-    return this.hasRange()
-      ? new Range90k(this.startTime90k, this.endTime90k)
-      : null;
+    return this.hasRange() ?
+      new Range90k(this.startTime90k, this.endTime90k) :
+      null;
   }
 
   /**
@@ -167,9 +167,9 @@ export default class CalendarTSRange {
    */
   _setRangeTime(range, dateStr, timeStr, dateOnlyThenEndOfDay) {
     const newTs90k = this._timeParser.parseDateTime90k(
-      dateStr,
-      timeStr,
-      dateOnlyThenEndOfDay
+        dateStr,
+        timeStr,
+        dateOnlyThenEndOfDay
     );
     if (newTs90k !== null) {
       range.dateStr = dateStr;

ui-src/lib/models/Range90k.js

@@ -37,7 +37,7 @@ import Range from './Range';
  *
  * @type {WeakMap}
  */
-let _range = new WeakMap();
+const _range = new WeakMap();
 
 /**
  * Class like Range to represent ranges over timestamps in 90k format.
@@ -94,8 +94,8 @@ export default class Range90k {
    */
   trimmed(against) {
     return new Range90k(
-      Math.max(this.startTime90k, against.startTime90k),
-      Math.min(this.endTime90k, against.endTime90k)
+        Math.max(this.startTime90k, against.startTime90k),
+        Math.min(this.endTime90k, against.endTime90k)
     );
   }
 

ui-src/lib/models/Recording.js

@@ -102,7 +102,7 @@ export default class Recording {
    * @return {Range90k}                Resulting range
    */
   range90k(trimmedAgainst = null) {
-    let result = new Range90k(this.startTime90k, this.endTime90k);
+    const result = new Range90k(this.startTime90k, this.endTime90k);
     return trimmedAgainst ? result.trimmed(trimmedAgainst) : result;
   }
   /**

ui-src/lib/models/Stream.js

@@ -65,9 +65,9 @@ export default class Stream {
    */
   get range90k() {
     return new Range90k(
-      this.json_.minStartTime90k,
-      this.json_.maxEndTime90k,
-      this.json_.totalDuration90k
+        this.json_.minStartTime90k,
+        this.json_.maxEndTime90k,
+        this.json_.totalDuration90k
     );
   }
 
@@ -94,11 +94,11 @@ export default class Stream {
    */
   get days() {
     return new Map(
-      Object.entries(this.json_.days).map(function(t) {
-        let [k, v] = t;
-        v = new Range90k(v.startTime90k, v.endTime90k, v.totalDuration90k);
-        return [k, v];
-      })
+        Object.entries(this.json_.days).map(function(t) {
+          let [k, v] = t;
+          v = new Range90k(v.startTime90k, v.endTime90k, v.totalDuration90k);
+          return [k, v];
+        })
     );
   }
 }