ci: Don't cache Firefox install

Two important notes:

1. The time it takes to download is negligble compared to e2e test runs
2. Since we cannot use environment variables in CircleCI cache keys we
   can't cache the download correctly and have it update when we switch
   firefox versions—this isn't the end of the world because of point 1

.circleci/config.yml

@@ -5,7 +5,6 @@ workflows:
   full_test:
     jobs:
       - prep-deps-npm
-      - prep-deps-firefox
       - prep-build:
           requires:
             - prep-deps-npm
@@ -28,7 +27,6 @@ workflows:
       - test-e2e-firefox:
           requires:
             - prep-deps-npm
-            - prep-deps-firefox
             - prep-build
       - test-e2e-beta-chrome:
           requires:
@@ -37,7 +35,6 @@ workflows:
       - test-e2e-beta-firefox:
           requires:
             - prep-deps-npm
-            - prep-deps-firefox
             - prep-build
       - test-unit:
           requires:
@@ -49,7 +46,6 @@ workflows:
       - test-integration-mascara-firefox:
           requires:
             - prep-deps-npm
-            - prep-deps-firefox
             - prep-scss
       - test-integration-flat-chrome:
           requires:
@@ -58,7 +54,6 @@ workflows:
       - test-integration-flat-firefox:
           requires:
             - prep-deps-npm
-            - prep-deps-firefox
             - prep-scss
       - all-tests-pass:
           requires:
@@ -113,20 +108,6 @@ jobs:
           key: v1.0-dependency-cache-{{ checksum "package-lock.json" }}
           paths:
             - node_modules
-  prep-deps-firefox:
-    docker:
-      - image: circleci/node:8.11.3-browsers
-    steps:
-      - checkout
-      - restore_cache:
-          key: v1.0-dependency-cache-firefox-
-      - run:
-          name: Download Firefox If needed
-          command: ./.circleci/scripts/firefox-download.sh
-      - save_cache:
-          key: v1.0-dependency-cache-firefox-
-          paths:
-            - firefox
 
   prep-build:
     docker:
@@ -224,11 +205,9 @@ jobs:
       - image: circleci/node:8.11.3-browsers
     steps:
       - checkout
-      - restore_cache:
-          key: v1.0-dependency-cache-firefox-
       - run:
-          name: Install firefox
-          command: ./.circleci/scripts/firefox-install.sh
+          name: Install Firefox
+          command: ./.circleci/scripts/firefox-install
       - restore_cache:
           key: v1.0-dependency-cache-{{ checksum "package-lock.json" }}
       - restore_cache:
@@ -261,11 +240,9 @@ jobs:
       - image: circleci/node:8.11.3-browsers
     steps:
       - checkout
-      - restore_cache:
-          key: v1.0-dependency-cache-firefox-
       - run:
-          name: Install firefox
-          command: ./.circleci/scripts/firefox-install.sh
+          name: Install Firefox
+          command: ./.circleci/scripts/firefox-install
       - restore_cache:
           key: v1.0-dependency-cache-{{ checksum "package-lock.json" }}
       - restore_cache:
@@ -356,17 +333,13 @@ jobs:
           command: npm run test:coverage
 
   test-integration-flat-firefox:
-    environment:
-      browsers: '["Firefox"]'
     docker:
       - image: circleci/node:8.11.3-browsers
     steps:
       - checkout
-      - restore_cache:
-          key: v1.0-dependency-cache-firefox-
       - run:
-          name: Install firefox
-          command: ./.circleci/scripts/firefox-install.sh
+          name: Install Firefox
+          command: ./.circleci/scripts/firefox-install
       - restore_cache:
           key: v1.0-dependency-cache-{{ checksum "package-lock.json" }}
       - run:
@@ -399,17 +372,13 @@ jobs:
           command: npm run test:flat
 
   test-integration-mascara-firefox:
-    environment:
-      browsers: '["Firefox"]'
     docker:
       - image: circleci/node:8.11.3-browsers
     steps:
       - checkout
-      - restore_cache:
-          key: v1.0-dependency-cache-firefox-
       - run:
-          name: Install firefox
-          command: ./.circleci/scripts/firefox-install.sh
+          name: Install Firefox
+          command: ./.circleci/scripts/firefox-install
       - restore_cache:
           key: v1.0-dependency-cache-{{ checksum "package-lock.json" }}
       - run:

.circleci/scripts/firefox-download.sh

@@ -1,13 +0,0 @@
-#!/usr/bin/env bash
-echo "Checking if firefox was already downloaded"
-if [ -d "firefox" ]
-then
-    echo "Firefox found. No need to download"
-else
-    FIREFOX_VERSION="61.0.1"
-    FIREFOX_BINARY="firefox-$FIREFOX_VERSION.tar.bz2"
-    echo "Downloading firefox..."
-    wget "https://ftp.mozilla.org/pub/firefox/releases/$FIREFOX_VERSION/linux-x86_64/en-US/$FIREFOX_BINARY" \
-    && tar xjf "$FIREFOX_BINARY"
-    echo "firefox download complete"
-fi

.circleci/scripts/firefox-install

@@ -0,0 +1,19 @@
+#!/usr/bin/env bash
+
+set -e
+set -u
+set -o pipefail
+
+FIREFOX_VERSION='61.0.1'
+FIREFOX_BINARY="firefox-${FIREFOX_VERSION}.tar.bz2"
+FIREFOX_BINARY_URL="https://ftp.mozilla.org/pub/firefox/releases/${FIREFOX_VERSION}/linux-x86_64/en-US/${FIREFOX_BINARY}"
+
+printf '%s\n' "Removing old Firefox installation"
+
+sudo rm -r /opt/firefox
+
+printf '%s\n' "Downloading & installing Firefox ${FIREFOX_VERSION}"
+
+wget --quiet --show-progress -O- "${FIREFOX_BINARY_URL}" | sudo tar xj -C /opt
+
+printf '%s\n' "Firefox ${FIREFOX_VERSION} installed"

.circleci/scripts/firefox-install.sh

@@ -1,8 +0,0 @@
-#!/usr/bin/env bash
-
-echo "Installing firefox..."
-sudo rm -r /opt/firefox
-sudo mv firefox /opt/firefox61
-sudo mv /usr/bin/firefox /usr/bin/firefox-old
-sudo ln -s /opt/firefox61/firefox /usr/bin/firefox
-echo "Firefox installed."