added travis and coverall

Author: ravi

.travis.yml

@@ -0,0 +1,18 @@
+language: python
+
+python:
+  - "2.7"
+  - "3.2"
+  - "3.3"
+  - "3.4"
+  - "3.5"
+
+install:
+  - python setup.py install
+  - pip install nose
+  - pip install coveralls
+script:
+  - nosetests  --with-coverage --cover-package=forex_python
+
+after_success:
+  coveralls

forex_python/converter.py

@@ -1,5 +1,4 @@
 import requests
-import datetime
 
 
 class RatesNotAvailableError(Exception):
@@ -20,11 +19,8 @@ def _source_url(self):
     def _get_date_string(self, date_obj):
         if date_obj is None:
             return 'latest'
-        try:
-            date_str = date_obj.strftime('%Y-%m-%d')
-            return date_str
-        except ValueError:
-            raise ValueError("Incorrect date String, date should be YYYY-MM-DD")
+        date_str = date_obj.strftime('%Y-%m-%d')
+        return date_str
 
 
 class CurrencyRates(Common):