Add GitHub Actions workflow to compile and test crate

.github/workflows/test.yml

+name: Test
+on:
+  - push
+  - pull_request
+jobs:
+  lint:
+    name: Lint
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v1
+      - name: Setup Rust stable
+        uses: actions-rs/toolchain@v1
+        with:
+          profile: minimal
+          toolchain: stable
+          override: true
+          components: rustfmt
+      - name: Check code format
+        uses: actions-rs/cargo@v1
+        with:
+          command: fmt
+          args: --all -- --check
+  test:
+    name: Test (${{ matrix.rust-toolchain }}, ${{ matrix.features }})
+    runs-on: ubuntu-latest
+    needs: lint
+    strategy:
+      matrix:
+        rust-toolchain:
+          - stable
+          - beta
+          - nightly
+        flags:
+          - ""
+          - "--target-cpu=native"
+    steps:
+    - name: Checkout code
+      uses: actions/checkout@v1
+    - name: Setup Rust ${{ matrix.rust-toolchain }}
+      uses: actions-rs/toolchain@v1
+      with:
+        profile: minimal
+        toolchain: ${{ matrix.rust-toolchain }}
+        override: true
+    - name: Setup cache for cargo
+      uses: actions/cache@v2
+      with:
+        path: target
+        key: ${{ runner.os }}-cargo-${{ matrix.rust-toolchain }}
+    - name: Test code
+      uses: actions-rs/cargo@v1
+      with:
+        env: RUSTFLAGS="${{ matrix.flags }}"
+        command: test
+  
\ No newline at end of file

README.md

@@ -13,7 +13,8 @@
 
 Motif scanning with position weight matrices (also known as position-specific 
 scoring matrices) is a robust method for identifying motifs of fixed length
-inside a biological sequence. They can be used to identiy
+inside a biological sequence. They can be used to identify transcription 
+factor binding sites in DNA, or protease cleavage site in polypeptides
 
 The `lightmotif` library provides a Rust crate to run very efficient 
 searches for a motif encoded in a position weight matrix. The position