Add .nvmrc file, switch to Node 12 (#932)

.circleci/config.yml

@@ -5,53 +5,46 @@ references:
     - checkout
     - restore_cache:
         keys:
-          - v2-dependencies-{{ .Environment.CIRCLE_JOB }}-{{ arch }}-{{ checksum "package.json" }}
+          - v3-dependencies-{{ .Environment.CIRCLE_JOB }}-{{ arch }}-{{ checksum "package.json" }}
     - run: npm install
     - run: npm run build
     - run: npm run ${BUILDTARGET}
     - run: npm run ${TESTTARGET}
     - save_cache:
-        key: v2-dependencies-{{ .Environment.CIRCLE_JOB }}-{{ arch }}-{{ checksum "package.json" }}
+        key: v3-dependencies-{{ .Environment.CIRCLE_JOB }}-{{ arch }}-{{ checksum "package.json" }}
         paths:
           - node_modules
 
 jobs:
-  unittest-node8:
+  unittest:
     docker:
-      - image: circleci/node:8-browsers
-    steps: *test-steps
-    environment:
-      BUILDTARGET: build:unittests
-      TESTTARGET: test:unit
-  unittest-node10:
-    docker:
-      - image: circleci/node:10-browsers
+      - image: circleci/node:12-browsers
     steps: *test-steps
     environment:
       BUILDTARGET: build:unittests
       TESTTARGET: test:unit
   uitest-firefox:
     docker:
-      - image: circleci/node:10-browsers
+      - image: circleci/node:12-browsers
     steps: *test-steps
     environment:
       BUILDTARGET: build:uitests
       TESTTARGET: test:ui firefox
   uitest-chrome:
     docker:
-      - image: circleci/node:10-browsers
+      - image: circleci/node:12-browsers
     steps: *test-steps
     environment:
       BUILDTARGET: build:uitests
       TESTTARGET: test:ui chrome
   lint:
     docker:
-      - image: circleci/node:8-browsers
+      - image: circleci/node:12-browsers
     steps:
       - checkout
       - restore_cache:
           keys:
-            - v2-dependencies-test-node8-{{ arch }}-{{ checksum "package.json" }}
+            - v3-dependencies-test-node12-{{ arch }}-{{ checksum "package.json" }}
       - run: npm install
       - run: npm run lint
   docker-build:
@@ -104,8 +97,7 @@ workflows:
   version: 2
   build:
     jobs:
-      - unittest-node8
-      - unittest-node10
+      - unittest
       - uitest-firefox
       - uitest-chrome
       - lint

.nvmrc

@@ -0,0 +1 @@
+12

README.md

@@ -57,9 +57,9 @@ is documented [here](https://threema-ch.github.io/app-remote-protocol/).
 
 Threema Web is written using [TypeScript](https://www.typescriptlang.org/) and
 [AngularJS 1](https://www.angularjs.org/). Dependencies are managed with
-[npm](https://www.npmjs.com/). You currently need Node.js 8 or later to build
-Threema Web. (Note that Node.js is only a build dependency, the result is plain
-old client-side JavaScript.)
+[npm](https://www.npmjs.com/). You currently need Node.js 12 to build Threema
+Web. (Note that Node.js is only a build dependency, the result is plain old
+client-side JavaScript.)
 
 Install development dependencies:
 
@@ -137,7 +137,7 @@ The configuration of Threema Web can be tweaked in `src/config.ts`:
 
 - `ICE_SERVERS`: Configuration object for the WebRTC STUN and ICE servers.
   Each URL may contain the substring `{prefix}`, which will be replaced by a
-  random byte represented as a lowercase hexadecimal value. 
+  random byte represented as a lowercase hexadecimal value.
 
 **Push**