[TD-2688] fix: make CI use gcc 4.8 and binutils 2.26 as minimal version toolchain requirements.

.travis.yml

@@ -158,7 +158,7 @@ matrix:
           - cmake
           - binutils-2.26
     env: 
-      - DESC="trusty/gcc-4.8 build"
+      - DESC="trusty/gcc-4.8/bintuils-2.26 build"
 
     before_script:
       - export TZ=Asia/Harbin
@@ -201,7 +201,7 @@ matrix:
     dist: bionic
     language: c
     compiler: clang
-    env: DESC="linux/clang build"
+    env: DESC="arm64 linux/clang build"
     git:
       - depth: 1
 
@@ -239,7 +239,7 @@ matrix:
           - build-essential
           - cmake
     env:
-      - DESC="xenial build"
+      - DESC="arm64 xenial build"
 
     before_script:
       - export TZ=Asia/Harbin

README.md

@@ -33,11 +33,17 @@ To build TDengine, use [CMake](https://cmake.org/) 3.5 or higher versions in the
 
 ## Install tools
 
-### Ubuntu & Debian:
+### Ubuntu 16.04 and above & Debian:
 ```bash
 sudo apt-get install -y gcc cmake build-essential git
 ```
 
+### Ubuntu 14.04:
+```bash
+sudo apt-get install -y gcc cmake3 build-essential git binutils-2.26
+export PATH=/usr/lib/binutils-2.26/bin:$PATH
+```
+
 To compile and package the JDBC driver source code, you should have a Java jdk-8 or higher and Apache Maven 2.7 or higher installed. 
 To install openjdk-8:
 ```bash