Allow custom CA_BUNDLE via SDC_SSL_VERIFY env (#140)

Author: Dave?

sdcclient/_common.py

@@ -26,7 +26,8 @@ def __init__(self, token="", sdc_url='https://app.sysdigcloud.com', ssl_verify=T
         if self.ssl_verify == None:
             self.ssl_verify = ssl_verify
         else:
-            self.ssl_verify = self.ssl_verify.lower() == 'true'
+            if self.ssl_verify.lower() in ['true', 'false']:
+                self.ssl_verify = self.ssl_verify.lower() == 'true'
 
     def __get_headers(self, custom_headers):
         headers = {