Issue #110 - Add RequestsLibrary in Docker Image

* Fixed failing tests

Author: ppodgorsek

test/requests.robot

@@ -10,7 +10,7 @@ Suite Teardown  Delete All Sessions
 Get Requests
     [Tags]  get
     Create Session  google  http://www.google.com
-    Create Session  github  https://api.github.com
+    Create Session  github  https://api.github.com verify=False
     ${resp}=  Get Request  google  /
     Should Be Equal As Strings  ${resp.status_code}  200
     ${resp}=  Get Request  github  /repos/ppodgorsek/docker-robot-framework