Fixing dependencies version. Split test and production requirements

.travis.yml

@@ -7,6 +7,7 @@ before_install:
     - pip install coveralls coverage
 install:
     - pip install -r requirements.txt
+    - pip install -r requirements-test.txt
 script:
     - coverage run -m py.test
     - coverage report -m

requirements-test.txt

@@ -0,0 +1 @@
+pytest==3.6.3

requirements.txt

@@ -1,3 +1 @@
-setuptools
-pytest
-ply
+ply==3.11

setup.py

@@ -9,6 +9,9 @@
 with open("requirements.txt", "r") as f:
     install_requires = [str(req) for req in pkg_resources.parse_requirements(f)]
 
+with open("requirements-test.txt", "r") as f:
+    install_test_requires = [str(req) for req in pkg_resources.parse_requirements(f)]
+
 setuptools.setup(
     name="blindtex",
     version="0.0.1",
@@ -22,7 +25,7 @@
     include_package_data = True,
     install_requires=install_requires,
     extras_require = {
-        'test': ['coverage', 'pytest', 'pytest-cov'],
+        'test': install_test_requires,
     },
     classifiers=(
         "Programming Language :: Python :: 3",