Update supported platforms and Build Environments (#956)

Author: lalitb

.github/workflows/build-ubuntu-1804.yml

@@ -0,0 +1,36 @@
+name: C/C++ CI on Ubuntu 18:04
+
+on:
+  push:
+    branches:
+    - master
+    - main
+    - dev
+    - dev/*
+    - release/*
+    - buildme/*
+
+  pull_request:
+    branches:
+    - master
+    - main
+    - dev
+
+  schedule:
+  - cron: 0 2 * * 1-5
+
+jobs:
+  build:
+
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        config: [release, debug]
+        os: [ubuntu-18.04]
+    
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v1
+      continue-on-error: true
+    - name: Test ${{ matrix.os }} ${{ matrix.config }}
+      run: ./build-tests.sh ${{ matrix.config }}

README.md

@@ -46,9 +46,9 @@ Other resources to learn how to setup the build system:
   | Mac OS X 10.12.6              | Clang Xcode 9.0, 9.1             |
   | Mac OS X 10.13.3              | Clang Xcode 9.2, 9.3, 10.0, 10.1 |
   | Raspbian GNU/Linux 8 (jessie) | GCC 4.9.2 (armv7l)               |
-  | Ubuntu 14.04.x LTS            | GCC 4.8.x, 4.9.4                 |
-  | Ubuntu 14.04.1 LTS            | GCC 5.x.x                        |
-  | Ubuntu 16.04 LTS              | GCC 5.x.x (armv7l)               |
+  | Ubuntu 14.04.x LTS            | GCC 5.x.x                        |
+  | Ubuntu 16.04 LTS              | GCC 5.x.x, GCC 5.x.x (armv7l)    |
+  | Ubuntu 18.04 LTS              | GCC 7.5.x                        |  
   | Windows 10                    | Android Studio/Gradle            |
   | Windows Server 2016           | Visual Studio 2017 (vc141)       |
   | Windows Server 2019           | Visual Studio 2019 (vc142)       |
@@ -63,7 +63,9 @@ Other resources to learn how to setup the build system:
   | Linux (x86, x64, arm, aarch64) | :white_check_mark: |                    |
   | Mac OS X 10.11+                | :white_check_mark: |                    |
   | Mac OS X (latest)              | :white_check_mark: | :white_check_mark: |
-  | Ubuntu 14.04.x LTS             | :white_check_mark: | :white_check_mark: |
+  | Ubuntu 14.04.x LTS             | :white_check_mark: |                    |
+  | Ubuntu 16.04.x LTS             | :white_check_mark: |                    |
+  | Ubuntu 18.04.x LTS             | :white_check_mark: | :white_check_mark: |
   | Ubuntu (latest)                | :white_check_mark: | :white_check_mark: |
   | Windows 7.1                    | :white_check_mark: |                    |
   | Windows 8.1                    | :white_check_mark: |                    |