Merge pull request #24 from meridianz/patch-1

Docs: fix typo in installation command line

docs/installation.rst

@@ -13,7 +13,7 @@ This requires librocksdb-dev>=5.0
     apt-get install python-virtualenv python-dev librocksdb-dev
     virtualenv venv
     source venv/bin/activate
-    pip install pythin-rocksdb
+    pip install python-rocksdb
 
 From source
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