fixes #107 @1h

:

.travis.yml

@@ -1,4 +1,5 @@
 os: linux
+dist: trusty
 language: cpp
 compiler: gcc
 
@@ -15,6 +16,5 @@ addons:
 
 script:
   - mkdir cmake-build
-  - cd cmake-build
-  - cmake .. 
+  - cd cmake-build && cmake ..
   - make all test 

CMakeLists.txt

@@ -2,11 +2,11 @@
 # Creation date: lundi 24 septembre 2018, 10:39:35 (UTC+0200)
 # Description: C++ threading library that mimics the C++11 standard implementation.
 #
-cmake_minimum_required(VERSION 3.11)
+cmake_minimum_required(VERSION 3.9)
 
 project(
   cpp-logger
-  VERSION 2.2.1
+  VERSION 2.3.0
   DESCRIPTION "Simple C++ logger (${GIT_LOG})")
 
 #find_package(Git CONFIG)

CONTRIBUTING.md

@@ -0,0 +1,49 @@
+# How to contribute
+
+I'm really glad you're reading this, because we need volunteer developers to help this project come to fruition.
+
+Here are some important resources:
+
+  * [Our roadmap](https://github.com/HerbertKoelman/cpp-logger/milestones) is the 10k foot view of where we're going, and
+  * Bugs? [GitHub cpp-logger issues](https://github.com/HerbertKoelman/cpp-logger/issues) is where to report them
+
+## Coding conventions
+
+Start reading our code and you'll get the hang of it. We optimize for readability:
+
+  * We indent using four spaces (soft tabs)
+  * We use [snake case](https://en.wikipedia.org/wiki/Snake_case) naming convention.
+  * We indent using K&R and Stroustrup variant (more [here](https://en.m.wikipedia.org/wiki/Indentation_style)).
+  * This is open source software. Consider the people who will read your code, and make it look nice for them. It's sort 
+    of like driving a car: Perhaps you love doing donuts when you're alone, but with passengers the goal is to make the 
+    ride as smooth as possible.
+  * When it comes to UML, we use PlantUML. You can store your diagrtams in `./diagrams/`, PlantUML files should use the 
+    extension `.puml` 
+
+## Testing
+
+We use [GoogleTest](https://github.com/google/googletest) to write and run unit tests. The cmake module `cmake/GTestExtConfig.cmake` 
+upload google test source code by cloning the GitHub's repository. The CMake flag `BUILD_TESTS` can be used to turn google testing off.
+
+Test programs are stored in `./tests/` and are setup through `./tests/CMakeLists.txt`
+
+## Submitting changes
+
+Please send a [GitHub Pull Request to cpp-logger](https://github.com/HerbertKoelman/cpp-logger/pulls) with a clear list 
+of what you've done (read more about [pull requests](http://help.github.com/pull-requests/)). When you send a pull request, 
+we will love you forever if you include Doxygen examples. We can always use more test coverage. Please follow our coding conventions 
+(below) and make sure all of your commits are atomic (one feature per commit).
+
+Always write a clear log message for your commits. One-line messages are fine for small changes, but bigger changes should look like this:
+
+    $ git commit -m "A brief summary of the commit
+    > 
+    > A paragraph describing what changed and its impact."
+
+## Continious integration
+
+We use [Travis-CI](https://travis-ci.org/HerbertKoelman/cpp-logger/) to build and run unit tests.
+
+Thanks,
+
+Herbert Koelman