Update contributing file

Author: Alvaro Navarro

.github/CONTRIBUTING.md

@@ -16,13 +16,11 @@ eval "$(pyenv init -)"
 Second, ensure you have a version of every Python we support installed. Your versions may differ.
 
 ```sh
-pyenv install 2.7.14
-pyenv install 3.3.7
 pyenv install 3.4.9
 pyenv install 3.5.6
 pyenv install 3.6.3
 pyenv install 3.6.8
-pyenv global 3.6.8 3.6.3 3.5.6 3.4.9 3.3.7 2.7.14   
+pyenv global 3.6.8 3.6.3 3.5.6 3.4.9
 ```
 
 Next ensure you create a virtual environment.
@@ -45,7 +43,7 @@ Alternatively, to run tests just against a specific Python version, create cover
 
 ```sh
 brew install fswatch
-pyenv shell 2.7.14
+pyenv shell 3.6.8
 make watch
 ```
 

.github/ISSUE_TEMPLATE.md

@@ -22,5 +22,5 @@ What version of Python/Pip are you running? What Operating System are you on?
 
 Please make sure you checked the following:
 
-* Are you running Python 2.7 or 3.6?
+* Which version of Python are you using?
 * Did you download the latest version of this package?

setup.py

@@ -20,7 +20,7 @@
     long_description=long_description,
     author='Amadeus',
     author_email='developers@amadeus.com',
-    python_requires='>=2.7.0',
+    python_requires='>=3.4.8',
     url='https://github.com/amadeus4dev/amadeus-python',
     install_requires=[],
     packages=find_packages(),