Fix testing on stable rust toolchain

.github/workflows/linux-tests-on-stable-toolchain

@@ -0,0 +1,53 @@
+name: Linux Tests
+on: [push]
+
+jobs:
+  test-stable:
+
+   strategy:
+      matrix:
+        os: [ubuntu-latest]
+    runs-on:
+      - ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v2
+      with:
+        fetch-depth: 0
+
+    - uses: actions-rs/toolchain@v1
+      with:
+        toolchain: stable
+        override: true
+
+    - uses: actions-rs/cargo@v1
+      with:
+        command: build
+        args: --release --all-features
+
+    - name: Install dependencies
+      run: |
+        pip install setuptools wheel
+
+    - name: Build cryptatools
+      run: cargo build --all
+
+    - name: Install cryptatools clis
+      run: cargo install --path ./cryptatools-cli
+
+    - name: Run tests
+      run: |
+        cargo test --all
+
+    - name: Generate documentation
+      run: |
+        cargo doc --package cryptatools-core --workspace --no-deps
+
+    - name: Build and install Python Bindings
+      run: |
+        python3 ./cryptatools-core/setup.py bdist_wheel --verbose ;
+        pip3 install ./dist/* --force-reinstall ;
+
+    - name: Test python bindings
+      run: |
+        python3 ./cryptatools-core/binding-testing/testing.py ;

cryptatools-core/src/lib.rs

@@ -1,6 +1,7 @@
 pub mod cryptanalysis;
 pub mod cryptography;
 pub mod utils;
+mod maths;
 
 use crate::utils::alphabets::{Encoding, Alphabet, split_bytes_by_characters_representation, uniffy_opcode_group};
 use crate::cryptography::classical::encryption::monoalphabetic_ciphers::caesar_number::CaesarNumberAlgorithm;

cryptatools-core/src/maths/mod.rs

@@ -0,0 +1 @@
+pub mod factoring;

cryptatools-core/src/utils/alphabets.rs

@@ -1,6 +1,5 @@
 use itertools::Itertools;
 use bimap::btree::BiBTreeMap;
-//use std::assert_matches::assert_matches;
 
 ///```
 /// use cryptatools_core::utils::{convert::Encode, alphabets::split_bytes_by_characters_representation, alphabets::Alphabet};
@@ -873,9 +872,6 @@ impl Alphabet {
     /// Returns: a converted human readable set of character text in the same order as the original unconverted text.
     ///
     /// ```
-    /// #![feature(assert_matches)]
-    /// 
-    /// use std::assert_matches::assert_matches;
     /// use cryptatools_core::utils::{convert::Encode, alphabets::split_bytes_by_characters_representation, alphabets::Alphabet};
     /// use cryptatools_core::utils::alphabets::Encoding;
     ///