Fix the npm install issue

If the you have encounter the problem when installing it. You can consider pull this commit
<pre>
npm install </pre>

<pre>
npm WARN package.json node-static@0.5.9 No repository field.
npm http GET https://registry.npmjs.org/geoip-no-city-leak/0.4.9-1
npm http GET https://registry.npmjs.org/socket.io/0.9.6
npm http 304 https://registry.npmjs.org/geoip-no-city-leak/0.4.9-1
npm http 304 https://registry.npmjs.org/socket.io/0.9.6

> geoip-no-city-leak@0.4.9-1 install /Users/zzn/ws/siyuan/hummingbird/node_modules/geoip-no-city-leak
> node-gyp rebuild

npm http GET https://registry.npmjs.org/redis/0.6.7
npm http GET https://registry.npmjs.org/policyfile/0.0.4
npm http GET https://registry.npmjs.org/socket.io-client/0.9.6
npm http 304 https://registry.npmjs.org/redis/0.6.7
npm http 304 https://registry.npmjs.org/policyfile/0.0.4
npm WARN package.json policyfile@0.0.4 No repository field.
npm WARN package.json policyfile@0.0.4 'repositories' (plural) Not supported.
npm WARN package.json Please pick one as the 'repository' field
  CXX(target) Release/obj.target/geoip/src/city.o
npm http 304 https://registry.npmjs.org/socket.io-client/0.9.6
npm http GET https://registry.npmjs.org/socket.io-client/-/socket.io-client-0.9.6.tgz
In file included from ../src/city.cc:7:
../src/city.h:12:10: fatal error: 'GeoIPCity.h' file not found
#include <GeoIPCity.h>
         ^
1 error generated.
make: *** [Release/obj.target/geoip/src/city.o] Error 1
gyp ERR! build error
gyp ERR! stack Error: `make` failed with exit code: 2
gyp ERR! stack     at ChildProcess.onExit (/usr/local/Cellar/node/0.10.12/lib/node_modules/npm/node_modules/node-gyp/lib/build.js:267:23)
gyp ERR! stack     at ChildProcess.EventEmitter.emit (events.js:98:17)
gyp ERR! stack     at Process.ChildProcess._handle.onexit (child_process.js:789:12)
gyp ERR! System Darwin 12.4.0
gyp ERR! command "node" "/usr/local/Cellar/node/0.10.12/lib/node_modules/npm/node_modules/node-gyp/bin/node-gyp.js" "rebuild"
gyp ERR! cwd /Users/zzn/ws/siyuan/hummingbird/node_modules/geoip-no-city-leak
gyp ERR! node -v v0.10.12
gyp ERR! node-gyp -v v0.10.0
gyp ERR! not ok
npm ERR! weird error 1
npm http 200 https://registry.npmjs.org/socket.io-client/-/socket.io-client-0.9.6.tgz
npm ERR! not ok code 0
13:36:45 zzn@zzn-macbookpro ⮁ ~ ⮁ ws ⮁ siyuan ⮁ hummingbird ⮀ master ⮀ $ ⮀npm install geoip-no-city-leak
npm WARN package.json node-static@0.5.9 No repository field.
npm http GET https://registry.npmjs.org/geoip-no-city-leak/0.4.9-1
npm http 304 https://registry.npmjs.org/geoip-no-city-leak/0.4.9-1

> geoip-no-city-leak@0.4.9-1 install /Users/zzn/ws/siyuan/hummingbird/node_modules/geoip-no-city-leak
> node-gyp rebuild

  CXX(target) Release/obj.target/geoip/src/city.o
In file included from ../src/city.cc:7:
../src/city.h:12:10: fatal error: 'GeoIPCity.h' file not found
#include <GeoIPCity.h>
         ^
1 error generated.
make: *** [Release/obj.target/geoip/src/city.o] Error 1
gyp ERR! build error
gyp ERR! stack Error: `make` failed with exit code: 2
gyp ERR! stack     at ChildProcess.onExit (/usr/local/Cellar/node/0.10.12/lib/node_modules/npm/node_modules/node-gyp/lib/build.js:267:23)
gyp ERR! stack     at ChildProcess.EventEmitter.emit (events.js:98:17)
gyp ERR! stack     at Process.ChildProcess._handle.onexit (child_process.js:789:12)
gyp ERR! System Darwin 12.4.0
gyp ERR! command "node" "/usr/local/Cellar/node/0.10.12/lib/node_modules/npm/node_modules/node-gyp/bin/node-gyp.js" "rebuild"
gyp ERR! cwd /Users/zzn/ws/siyuan/hummingbird/node_modules/geoip-no-city-leak
gyp ERR! node -v v0.10.12
gyp ERR! node-gyp -v v0.10.0
gyp ERR! not ok
npm ERR! weird error 1
npm ERR! not ok code 0
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