Changed pacakge dependencies for travis

Forced slowaes version.

.travis.yml

@@ -1,5 +1,5 @@
 language: python
 python:
     - "2.7"
-install: "pip install slowaes ecdsa>=0.9 pbkdf2 requests pyasn1 pyasn1-modules tlslite>=0.4.5 qrcode"
+install: "pip install slowaes==0.1a1 ecdsa>=0.9 pbkdf2 requests pyasn1 pyasn1-modules tlslite>=0.4.5 qrcode"
 script: nosetests lib