Upgrade lodash from 4.17.15 to 4.17.20 (#1759)

<h3>Snyk has created this PR to fix one or more vulnerable packages in the `npm` dependencies of this project.</h3>

![merge advice](https://app.snyk.io/badges/merge-advice/?package_manager=npm&package_name=lodash&from_version=4.17.15&to_version=4.17.20&pr_id=31842747-752f-42e7-b1f2-8fa3f51d0e21&visibility=true&has_feature_flag=false)



#### Changes included in this PR

- Changes to the following files to upgrade the vulnerable dependencies to a fixed version:
    - client/package.json
    - client/package-lock.json



#### Vulnerabilities that will be fixed
##### With an upgrade:
Severity                   | Priority Score (*)                   | Issue                   | Breaking Change                   | Exploit Maturity
:-------------------------:|-------------------------|:-------------------------|:-------------------------|:-------------------------
![high severity](https://res.cloudinary.com/snyk/image/upload/w_20,h_20/v1561977819/icon/h.png "high severity")  |  **776/1000**  <br/> **Why?** Recently disclosed, Has a fix available, CVSS 9.8  | Prototype Pollution <br/>[SNYK-JS-LODASH-590103](https://snyk.io/vuln/SNYK-JS-LODASH-590103) |  No  | No Known Exploit 

(*) Note that the real score may have changed since the PR was raised.











Check the changes in this PR to ensure they won't cause issues with your project.



------------



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🧐 [View latest project report](https://app.snyk.io/org/cellxgene/project/9195ddb9-6feb-469e-ad47-f5dc24c811fe)

🛠 [Adjust project settings](https://app.snyk.io/org/cellxgene/project/9195ddb9-6feb-469e-ad47-f5dc24c811fe/settings)

📚 [Read more about Snyk's upgrade and patch logic](https://support.snyk.io/hc/en-us/articles/360003891078-Snyk-patches-to-fix-vulnerabilities)

[//]: # (snyk:metadata:{"prId":"31842747-752f-42e7-b1f2-8fa3f51d0e21","dependencies":[{"name":"lodash","from":"4.17.15","to":"4.17.20"}],"packageManager":"npm","projectPublicId":"9195ddb9-6feb-469e-ad47-f5dc24c811fe","projectUrl":"https://app.snyk.io/org/cellxgene/project/9195ddb9-6feb-469e-ad47-f5dc24c811fe?utm_source=github&utm_medium=fix-pr","type":"auto","patch":[],"vulns":["SNYK-JS-LODASH-590103"],"upgrade":["SNYK-JS-LODASH-590103"],"isBreakingChange":false,"env":"prod","prType":"fix","templateVariants":["updated-fix-title","priorityScore","merge-advice-badge-shown"],"priorityScoreList":[776]})

client/package-lock.json

@@ -13787,9 +13787,9 @@
       }
     },
     "lodash": {
-      "version": "4.17.19",
-      "resolved": "https://registry.npmjs.org/lodash/-/lodash-4.17.19.tgz",
-      "integrity": "sha512-JNvd8XER9GQX0v2qJgsaN/mzFCNA5BRe/j8JN9d+tWyGLSodKQHKFicdwNYzWwI3wjRnaKPsGj1XkBjx/F96DQ=="
+      "version": "4.17.20",
+      "resolved": "https://registry.npmjs.org/lodash/-/lodash-4.17.20.tgz",
+      "integrity": "sha512-PlhdFcillOINfeV7Ni6oF1TAEayyZBoZ8bcshTHqOYJYlrqzRK5hagpagky5o4HfCzzd1TRkXPMFq6cKk9rGmA=="
     },
     "lodash._reinterpolate": {
       "version": "3.0.0",

client/package.json

@@ -52,7 +52,7 @@
     "gl-matrix": "^3.3.0",
     "gl-vec3": "^1.1.3",
     "is-number": "^7.0.0",
-    "lodash": "^4.17.19",
+    "lodash": "^4.17.20",
     "memoize-one": "^5.1.1",
     "react": "^16.13.1",
     "react-async": "^10.0.1",