use https instead of ssh auth on submodules

.gitmodules

@@ -1,8 +1,8 @@
 [submodule "CommonLibs"]
 	path = CommonLibs
-	url = git@github.com:RangeNetworks/CommonLibs.git
+	url = https://github.com/RangeNetworks/CommonLibs.git
 	branch = master
 [submodule "NodeManager"]
 	path = NodeManager
-	url = git@github.com:RangeNetworks/NodeManager.git
+	url = https://github.com/RangeNetworks/NodeManager.git
 	branch = master

.travis.yml

@@ -20,7 +20,6 @@ before_install:
  - ./build.sh
  - sudo dpkg -i *.deb
  - cd ..
- - sed -i 's/git@github.com:/git:\/\/github.com\//' .gitmodules
  - git submodule update --init --recursive
  - sudo ./NodeManager/install_libzmq.sh