Load Jinja2 during kytos setup

[diraol]

After solving #357 we still have an error during our setup.

Jinja2 is a requirement of our project (it is in requirements.txt), and is correctly installed by the setup procedure (python setup.yp install).
But as it is also used/loaded on the setup script, we are facing a timing problem.

The available (installed) modules from PYTHONPATH are loaded on the beginning of the setup.py script. During this script, all requirements are installed, including the Jinja2 package. But the available modules (sys.path) are not reloaded, thus Jinja2 is not available to be used inside the setup.py script, which raises an error during the install procedure.

If the setup is run again, everything works fine (since Jinja2 was installed on the first run).

So, we need to figure out how to load (import) jinja2 on the setup.py script "on the runtime".

[beraldoleal]

@diraol try... except... import on proper place will not work ? Besides that.. We have to figure out what is the best way to get values from "user/config file" during setup procedure.

[diraol]

@beraldoleal we can use a try/except over there, no problem. But if the Jinja2 package was installed during the install procedure it will not be available to the importer on any part of the setup script without reloading the packages available on the sys.path.

Regarding the "user/config file", I didn't understood what value should we get from user/config file that would alter anything related to this issue....

[beraldoleal]

@diraol exact.

try:
  import jinja2
except ImportErrorBlabla:
  do your function to insert to the path here

Makes sense ?

[diraol]

Yeap, no problems with that. =)