Merge pull request #1470 from freqtrade/fix/installscript

fix and improve installation script

setup.sh

@@ -17,6 +17,11 @@ function check_installed_python() {
         return
    fi
 
+   if [ -z ${PYTHON} ]; then
+        echo "No usable python found. Please make sure to have python3.6 or python3.7 installed"
+        exit 1
+   fi
+
 }
 
 function updateenv() {
@@ -25,15 +30,14 @@ function updateenv () {
     echo "-------------------------"
     source .env/bin/activate
     echo "pip3 install in-progress. Please wait..."
-    pip3 install --quiet --upgrade pip
-    pip3 install --quiet -r requirements.txt --upgrade
-    pip3 install --quiet -r requirements.txt
+    # Install numpy first to have py_find_1st install clean
+    pip3 install --upgrade pip numpy
+    pip3 install --upgrade -r requirements.txt
 
     read -p "Do you want to install dependencies for dev [Y/N]? "
     if [[ $REPLY =~ ^[Yy]$ ]]
     then
-        pip3 install --quiet -r requirements-dev.txt --upgrade
-        pip3 install --quiet -r requirements-dev.txt
+        pip3 install --upgrade -r requirements-dev.txt
     else
         echo "Dev dependencies ignored."
     fi
@@ -45,6 +49,11 @@ function updateenv () {
 
 # Install tab lib
 function install_talib() {
+    if [ -f /usr/local/lib/libta_lib.a ]; then
+        echo "ta-lib already installed, skipping"
+        return
+    fi
+
     cd build_helpers
     tar zxvf ta-lib-0.4.0-src.tar.gz
     cd ta-lib