Error parsing `mins` and `ns` time units since items()

[shamsimam]

pymesos/pymesos/utils.py

Line 20 in b7b5ddf

if s.endswith(n):

>>> parse_duration('5mins')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<stdin>", line 10, in parse_duration
ValueError: could not convert string to float: '5mi'