Auto merge of #13171 - emilio:mako-is-back, r=SimonSapin

Revert "Remove mako.zip"

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Stylo doesn't use Servo's virtualenv, so we need to integrate it into Gecko's build before doing this.

---
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- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors

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- [x] There are tests for these changes OR

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This reverts commit 95e3f8333a.

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components/style/properties/build.py

@@ -7,6 +7,7 @@ import os.path
 import sys
 
 BASE = os.path.dirname(__file__.replace('\\', '/'))
+sys.path.insert(0, os.path.join(BASE, "Mako-0.9.1.zip"))
 sys.path.insert(0, BASE)  # For importing `data.py`
 
 from mako import exceptions

python/requirements.txt

@@ -10,7 +10,6 @@ toml == 0.9.1
 flake8 == 2.4.1
 pep8 == 1.5.7
 pyflakes == 0.8.1
-mako == 0.9.1
 
 # For test-webidl
 ply == 3.8