Update gitpod configuration

According to some setup docs and example in workspace-full Dockerfile.

.gitpod.Dockerfile

@@ -3,19 +3,25 @@ FROM gitpod/workspace-full
 USER gitpod
 
 RUN sudo apt-get update \
-    && sudo apt-get install -y --no-install-recommends \
+    && sudo apt-get install -yq \
         pkg-config \
         libpython3.6 \
         rust-lldb \
-        qemu \
-        gdb \
-    && .cargo/bin/rustup target add aarch64-linux-android \
-    && .cargo/bin/rustup component add clippy llvm-tools-preview rls rust-analysis rustfmt rust-src \
-    && .cargo/bin/cargo install cargo-bloat cargo-asm cargo-expand cargo-graph \
-        cargo-binutils cargo-geiger cargo-cache cargo-make just \
-    && .cargo/bin/cargo cache -i \
-    && .cargo/bin/cargo cache -e \
-    && .cargo/bin/cargo cache -i \
-    && sudo rm -rf /var/lib/apt/lists/*
+        qemu-system-aarch64 \
+        gdb-multiarch \
+    && sudo apt-get clean \
+    && sudo rm -rf /tmp/*
 
-ENV RUST_LLDB=/usr/bin/lldb-8
+RUN .cargo/bin/rustup toolchain install nightly \
+    && .cargo/bin/rustup default nightly \
+    && .cargo/bin/rustup toolchain uninstall 1.48.0 \
+    && .cargo/bin/rustup component add clippy llvm-tools-preview rls rust-analysis rust-src rustfmt \
+    && .cargo/bin/rustup target add aarch64-unknown-none-softfloat
+
+RUN bash -lc "cargo install cargo-asm cargo-binutils cargo-bloat cargo-cache cargo-expand cargo-fmt cargo-geiger cargo-graph cargo-make just"
+
+RUN bash -lc "cargo cache -i && cargo cache -e && cargo cache -i"
+
+ENV RUST_LLDB=/usr/bin/lldb-9
+ENV GDB=/usr/bin/gdb-multiarch
+ENV QEMU=/usr/bin/qemu-system-aarch64

.gitpod.yml

@@ -1,6 +1,14 @@
 image:
   file: .gitpod.Dockerfile
 
+tasks:
+  - name: Clippy
+    command: just clippy
+  - name: Testing
+    command: just test
+  - name: Build
+    command: just build
+
 github:
   prebuilds:
     master: true