[travis] Make travis faster

.travis.yml

@@ -6,16 +6,24 @@ env:
   global:
   - COMPILER=g++
 
+# Default --recursive (rapidjson/thirdparty/gtest) is unnecessary
+git:
+  submodules: false
+  depth: 3
+
+before_install:
+  - git submodule update --init
+
 addons:
   apt:
     sources: &apt_sources
       - ubuntu-toolchain-r-test
       - llvm-toolchain-precise-3.5
-      - llvm-toolchain-precise-3.6
-      - llvm-toolchain-precise-3.7
-      - llvm-toolchain-precise-3.8
-      - llvm-toolchain-trusty-3.9
-      - llvm-toolchain-trusty-4.0
+      #- llvm-toolchain-precise-3.6
+      #- llvm-toolchain-precise-3.7
+      #- llvm-toolchain-precise-3.8
+      #- llvm-toolchain-trusty-3.9
+      #- llvm-toolchain-trusty-4.0
       - llvm-toolchain-trusty-5.0
 
 compiler: clang

wscript

@@ -93,7 +93,7 @@ def download_and_extract(destdir, url, ext):
   dest = destdir + ext
 
   # Extract the tarball.
-  if not os.path.isdir(destdir):
+  if not os.path.isdir(os.path.join(destdir, 'include')):
     # Download and save the compressed tarball as |compressed_file_name|.
     if not os.path.isfile(dest):
       print('Downloading tarball')