Upgrade js-yaml to 3.10.0.

The main fix we are wanting is outputting astral characters (emojis) as
a single escape instead of surrogate pairs: nodeca/js-yaml#368.

yarn.lock

@@ -4582,13 +4582,20 @@ js-tokens@^3.0.0, js-tokens@^3.0.2:
   version "3.0.2"
   resolved "https://registry.yarnpkg.com/js-tokens/-/js-tokens-3.0.2.tgz#9866df395102130e38f7f996bceb65443209c25b"
 
-js-yaml@^3.4.2, js-yaml@^3.4.3, js-yaml@^3.5.1, js-yaml@^3.7.0, js-yaml@^3.8.1:
+js-yaml@^3.4.2, js-yaml@^3.4.3, js-yaml@^3.5.1, js-yaml@^3.8.1:
   version "3.9.1"
   resolved "https://registry.yarnpkg.com/js-yaml/-/js-yaml-3.9.1.tgz#08775cebdfdd359209f0d2acd383c8f86a6904a0"
   dependencies:
     argparse "^1.0.7"
     esprima "^4.0.0"
 
+js-yaml@^3.7.0:
+  version "3.10.0"
+  resolved "https://registry.yarnpkg.com/js-yaml/-/js-yaml-3.10.0.tgz#2e78441646bd4682e963f22b6e92823c309c62dc"
+  dependencies:
+    argparse "^1.0.7"
+    esprima "^4.0.0"
+
 js-yaml@~3.7.0:
   version "3.7.0"
   resolved "https://registry.yarnpkg.com/js-yaml/-/js-yaml-3.7.0.tgz#5c967ddd837a9bfdca5f2de84253abe8a1c03b80"