Remove -std=c++14 and -std=c++17 from .travis.yml.

Travis has too old compilers in their OS images and I don't want bother
with their upgrading.

.travis.yml

@@ -19,10 +19,11 @@ env:
     - CFLAGS="-std=c11 -pedantic" CONFIG=Release
     - CXXFLAGS="-std=c++11 -pedantic" CONFIG=Debug      # C++11
     - CXXFLAGS="-std=c++11 -pedantic" CONFIG=Release
-    - CXXFLAGS="-std=c++14 -pedantic" CONFIG=Debug      # C++14
-    - CXXFLAGS="-std=c++14 -pedantic" CONFIG=Release
-    - CXXFLAGS="-std=c++17 -pedantic" CONFIG=Debug      # C++17
-    - CXXFLAGS="-std=c++17 -pedantic" CONFIG=Release
+    # Too old compilers on travis-ci.org for these:
+    #- CXXFLAGS="-std=c++14 -pedantic" CONFIG=Debug      # C++14
+    #- CXXFLAGS="-std=c++14 -pedantic" CONFIG=Release
+    #- CXXFLAGS="-std=c++17 -pedantic" CONFIG=Debug      # C++17
+    #- CXXFLAGS="-std=c++17 -pedantic" CONFIG=Release
 
 before_script:
     - mkdir build

README.md

@@ -1,3 +1,7 @@
+[![Build status (travis-ci.com)](https://img.shields.io/travis/mity/acutest/master.svg?label=linux%20build)](https://travis-ci.org/mity/acutest)
+[![Build status (appveyor.com)](https://img.shields.io/appveyor/ci/mity/acutest/master.svg?label=windows%20build)](https://ci.appveyor.com/project/mity/acutest/branch/master)
+
+
 # Acutest Readme
 
 Home: http://github.com/mity/acutest