install fasttesxt using pip git feature

Author: rosbo

Dockerfile

@@ -341,7 +341,7 @@ RUN pip install --upgrade cython && \
     pip install --upgrade cysignals && \
     pip install pyfasttext && \
     pip install ktext && \
-    cd /usr/local/src && git clone --depth=1 https://github.com/facebookresearch/fastText.git && cd fastText && pip install . && \
+    pip install git+git://github.com/facebookresearch/fastText.git && \
     apt-get install -y libhunspell-dev && pip install hunspell && \
     pip install annoy && \
     pip install category_encoders && \