Update instructions for v1.1.0

Author: azubieta

Dockerfile

@@ -1,19 +1,27 @@
 FROM ubuntu:20.04
 ENV DEBIAN_FRONTEND=noninteractive
 
-RUN apt-get update && apt-get -yq install python3 python3-setuptools python3-pip wget fakeroot gnupg2 libglib2.0-bin file \
- desktop-file-utils libgdk-pixbuf2.0-dev librsvg2-dev libyaml-dev zsync gtk-update-icon-cache strace elfutils
-
-ADD . /opt/appimage-builder
-
-WORKDIR /opt/appimage-builder
-RUN python3 ./setup.py install && rm -rf /opt/appimage-builder
-
-RUN wget https://github.com/AppImage/AppImageKit/releases/download/13/appimagetool-x86_64.AppImage -O /opt/appimagetool \
-    && chmod +x /opt/appimagetool \
-    && cd /opt/; sed -i 's|AI\x02|\x00\x00\x00|' appimagetool; /opt/appimagetool --appimage-extract \ 
-    && mv /opt/squashfs-root /opt/appimagetool.AppDir \
-    && ln -s /opt/appimagetool.AppDir/AppRun /usr/local/bin/appimagetool
+RUN apt-get update && \
+    apt-get -yq install \
+        breeze-icon-theme \
+        desktop-file-utils \
+        elfutils \
+        fakeroot \
+        file \
+        git \
+        gnupg2 \
+        gtk-update-icon-cache \
+        libgdk-pixbuf2.0-dev \
+        libglib2.0-bin \
+        librsvg2-dev \
+        libyaml-dev \
+        python3 \
+        python3-pip \
+        python3-setuptools \
+        strace \
+        wget \
+        zsync && \
+    apt-get -yq autoclean
 
 WORKDIR /tmp
 RUN wget https://github.com/NixOS/patchelf/releases/download/0.12/patchelf-0.12.tar.bz2; \
@@ -22,5 +30,8 @@ RUN wget https://github.com/NixOS/patchelf/releases/download/0.12/patchelf-0.12.
     ./configure && make && make install; \
     rm -rf patchelf-*
 
+ADD . /opt/appimage-builder
+RUN python3 -m pip install /opt/appimage-builder
+RUN rm -rf /opt/appimage-builder
+
 WORKDIR /
-RUN apt-get -yq autoclean