upgrade buntdb

Resolves CVE-2021-42836, which probably didn't affect us, but we might as well
upgrade.

vendor/github.com/tidwall/gjson/SYNTAX.md

@@ -135,6 +135,37 @@ changed in v1.3.0 as to avoid confusion with the new [multipath](#multipaths)
 syntax. For backwards compatibility, `#[...]` will continue to work until the
 next major release.*
 
+The `~` (tilde) operator will convert a value to a boolean before comparison.
+
+For example, using the following JSON:
+
+```json
+{
+  "vals": [
+    { "a": 1, "b": true },
+    { "a": 2, "b": true },
+    { "a": 3, "b": false },
+    { "a": 4, "b": "0" },
+    { "a": 5, "b": 0 },
+    { "a": 6, "b": "1" },
+    { "a": 7, "b": 1 },
+    { "a": 8, "b": "true" },
+    { "a": 9, "b": false },
+    { "a": 10, "b": null },
+    { "a": 11 }
+  ]
+}
+```
+
+You can now query for all true(ish) or false(ish) values:
+
+```
+vals.#(b==~true)#.a    >> [1,2,6,7,8]
+vals.#(b==~false)#.a   >> [3,4,5,9,10,11]
+```
+
+The last value which was non-existent is treated as `false`
+
 ### Dot vs Pipe
 
 The `.` is standard separator, but it's also possible to use a `|`. 
@@ -205,6 +236,8 @@ There are currently the following built-in modifiers:
 - `@valid`: Ensure the json document is valid.
 - `@flatten`: Flattens an array.
 - `@join`: Joins multiple objects into a single object.
+- `@keys`: Returns an array of keys for an object.
+- `@values`: Returns an array of values for an object.
 
 #### Modifier arguments
 
@@ -260,8 +293,8 @@ gjson.AddModifier("case", func(json, arg string) string {
 ### Multipaths
 
 Starting with v1.3.0, GJSON added the ability to join multiple paths together
-to form new documents. Wrapping comma-separated paths between `{...}` or 
-`[...]` will result in a new array or object, respectively.
+to form new documents. Wrapping comma-separated paths between `[...]` or
+`{...}` will result in a new array or object, respectively.
 
 For example, using the given multipath