Add Python 3.8 support

Prefer calling time.process_time() instead of time.clock() (which was
deprecated in Python 3.3 and removed in Python 3.8). In addition, add
Python 3.8 to the Travis CI build matrix.

Author: iKevinY

.travis.yml

@@ -1,11 +1,9 @@
 language: python
 python:
   - "2.7"
-  - "3.2"
-  - "3.3"
-  - "3.4"
   - "3.5"
   - "3.6"
-sudo: false
+  - "3.7"
+  - "3.8"
 cache: pip
 script: nosetests

EulerPy/utils.py

@@ -23,10 +23,14 @@ def problem_glob(extension='.py'):
 
     def clock():
         """
-        Under Windows, system CPU time can't be measured. Return time.clock()
-        as user time and None as system time.
+        Under Windows, system CPU time can't be measured. Return
+        time.process_time() as user time and None as system time.
         """
-        return time.clock(), None
+        # Legacy support for Python 3.2 and earlier.
+        if sys.version_info < (3, 3, 0):
+            return time.clock(), None
+
+        return time.process_time(), None
 
 else:
     def clock():